(Mak) A dissertation submitted to the school of graduate studies in

Transcription

MAKERERE
UNIVERSITY
FACULTY OF TECHNOLOGY
The reliability of broadcast equipment as a factor affecting the
profitability of TV stations in Uganda
BY
ENG. Nicholas Ssemujju. BSC (ENG) (Mak)
A dissertation submitted to the school of graduate studies in
partial fulfillment for the award of the Degree Of Master OF
Engineering of Makerere University
JULY 2010
DECLARATION
1
I Nicholas Ssemujju declare that this piece of work is my original effort and has never been
submitted to any institution known to me for any award. All pieces of work that are not my original
effort contained herein have been duly referenced and mention of authors or origin made
accordingly.
Signed________________
Date _________________
2
APPROVAL
Supervisor 1
The following research report by Nicholas Ssemujju, which has been made under my supervision,
has been submitted to the School of Graduate Studies with my approval.
Name_________________
Sign__________________
Date__________________
Supervisor 2
The following research report by Nicholas Ssemujju, which has been made under my supervision,
has been submitted to the School of Graduate Studies with my approval.
Name_________________
Sign__________________
Date__________________
3
 Nicholas Ssemujju 2010
4
DEDICATION
Dedicated to Catherine Olive Ssemujju
5
ACKNOWLEDGEMENTS
I would like to thank my supervisors Dr. E. Lugujjo and Dr. J.K. Byaruhanga for the guidance given
to me during the conducting of this research and writing of this report. I would also like to thank all
staff of UTV and WBS TV who assisted me in the acquisition of data. Special mention in this
regard goes to Mr. Kazooba (WBS), Mr Nankunda (WBS) , Mr Patrick Sembajjo (WBS) , Mr
Ahmed Senabulya (WBS) and Mr. Francis Kakwenda (UTV).
6
TABLE OF CONTENTS
DECLARATION................................................................................................................................ 1
APPROVAL ....................................................................................................................................... 3
DEDICATION.................................................................................................................................... 5
ACKNOWLEDGEMENTS .............................................................................................................. 6
LIST OF ACRONYMS ................................................................................................................... 12
LIST OF SYMBOLS ....................................................................................................................... 13
ABSTRACT ...................................................................................................................................... 14
INTRODUCTION............................................................................................................................ 16
1.1
Background ........................................................................................................................ 16
1.2
Maintenance Regimes ........................................................................................................ 22
1.3
The Relationship Between Maintenance, Reliability and Profitability ............................. 23
1.4
Statement of the Problem ................................................................................................... 24
1.5
General Objective .............................................................................................................. 25
1.6
Specific Objectives ............................................................................................................ 25
1.7
Significance of the Problem ............................................................................................... 26
1.8
Scope of Research .............................................................................................................. 28
1.9
Choice of TV stations ........................................................................................................ 28
1.11 Statement of Hypothesis .................................................................................................... 29
1.11.1
Alternative hypothesis: .............................................................................................. 29
1.11.2
Null hypothesis: ........................................................................................................ 29
1.12 Assumptions....................................................................................................................... 29
1.13 Research Questions ............................................................................................................ 30
1.14 Limitations ......................................................................................................................... 31
REVIEW OF RELATED LITERATURE..................................................................................... 32
2.1
Introduction ........................................................................................................................ 32
2.2
The Development of Maintenance Records:...................................................................... 32
2.2.1 Definition of Reliability ................................................................................................. 38
2.2.2 Definition of observed failure rate: ................................................................................ 39
2.2.3 Definition of the observed mean time between failures: ............................................... 39
2.2.4 Inter relationship of terms: ............................................................................................. 39
2.3
Factors that Affect Equipment Reliability ........................................................................ 40
2.4
Condition Based Maintenance ........................................................................................... 41
2.5
Research on Reliability of TV Studio Broadcast Equipment ............................................ 42
2.6
Methods of Analysis of Failure Data ................................................................................. 43
2.6.1 Pareto Analysis .............................................................................................................. 43
2.6.2 The Chi Square Test......................................................................................................... 45
2.6.3 Two tailed t distribution ................................................................................................... 45
2.8
The Gap.............................................................................................................................. 47
2.9
Overview of Uganda Television ........................................................................................ 47
2.10 Overview of WBS TV ....................................................................................................... 50
2.11 Spares Purchase Policies .................................................................................................... 51
2.12 Recent Developments in Television Broadcasting Technology ...................................... 52
METHODOLOGY .......................................................................................................................... 54
3.1
Study Area ......................................................................................................................... 54
3.2
Choice of Sampling Elements in UTV .............................................................................. 54
7
3.2.1 Video Tape Recorders: .................................................................................................. 54
3.2.2 Video Monitors: ............................................................................................................. 54
3.2.3 Video Cameras:.............................................................................................................. 55
3.3
Choice of Sampling Elements in WBS TV........................................................................ 55
3.4
Research Instruments ......................................................................................................... 56
3.4.1 Job Cards:....................................................................................................................... 56
3.4.2 Questionnaire: ................................................................................................................ 57
3.4.3 Spares Parts lists: ........................................................................................................... 57
3.4.4 Interviews:...................................................................................................................... 57
3.5
Methods of Data Gathering in UTV .................................................................................. 58
3.6
Methods of Data Gathering in WBS TV............................................................................ 58
3.7
Purpose of Collecting Data from Workshop Job cards and Questionnaires ...................... 59
3.8
Collection of Data from Equipment Catalogues and Manuals .......................................... 60
3.9
Collection of data from available documents and interviews ............................................ 60
PRESENTATION AND INTERPRETATION OF RESULTS ................................................... 61
4.1
Introduction ........................................................................................................................ 61
4.2
Challenges of Maintenance in UTV .................................................................................. 61
4.3
UTV Central Workshop ..................................................................................................... 62
4.4
Maintenance Documentation ............................................................................................. 63
4.5
Workshop Equipment Inventory ........................................................................................ 66
4.6
Maintenance Evaluation and Costing ................................................................................ 66
4.7
Maintenance Strategies and Forms .................................................................................... 66
4.8
Engineering Stores Management ....................................................................................... 66
4.8.1 Entering items in store ................................................................................................... 66
4.8.2 Storage locations ............................................................................................................ 67
4.8.3 Issuing of items from the store....................................................................................... 68
4.9
Challenges of Maintenance in WBS TV ............................................................................ 68
4.10 Costs of Equipment failure ................................................................................................ 72
4.11 Tabulation of Data Obtained in UTV ................................................................................ 72
4.11.1
Mean Time Between Failure as a Reliability Parameter ........................................... 73
4.11.2
Cost of Spares per Machine per Year as a Maintenance Cost Parameter .................. 74
4.11.3 Frequency of Replacement of Identical Spare Parts as a Maintenance Cost Parameter . 75
4.12 Summary of Raw data from UTV ...................................................................................... 75
4.13 Tabulation of Data Obtained from WBS TV ..................................................................... 78
4.13.1
Mean Time between Failure as a Reliability Parameter ............................................ 79
4.13.2
Cost of Spares per Machine per Year as a Maintenance Cost Parameter. ................. 79
4.14 Summary of Raw data from WBS TV ............................................................................... 80
DISCUSSION OF RESULTS ......................................................................................................... 84
5.1
Introduction ........................................................................................................................ 84
5.2
Comparison of the UTV and WBS TV Maintenance Models ........................................... 84
5.3
Calculation of MTBF and Cost of spares per machine ...................................................... 86
5.3.1 Statistical Treatment of Data Obtained from UTV ........................................................ 86
5.3.2 Calculation of Equipment Hours of Use per Day in UTV ............................................. 89
5.3.3 Statistical Treatment of Data Obtained from WBS TV ..................................................... 89
5.4
Comparison of wages for maintenance staff between UTV and WBS .............................. 93
5.5
Graphical representation of MTBF and maintenance costs in UTV and WBS ................. 93
5.6
Pareto Analysis .................................................................................................................. 95
8
5.6.1 Graphical Representation of Results of Pareto Analysis ............................................... 97
5.7
The cost of spares versus frequency of maintenance ......................................................... 99
5.8
Testing of hypothesis ....................................................................................................... 101
5.8.1 Alternative hypothesis ................................................................................................. 101
5.8.2 Null hypothesis ............................................................................................................ 101
5.8.3 Testing hypothesis for the case of video tape recorders in UTV ................................. 101
5.8.4 Testing hypothesis for the case of video monitors in UTV ......................................... 102
5.8.5 Testing hypothesis for the case of video cameras in UTV .......................................... 102
5.8.6 Testing hypothesis for the case of videotape recorders in WBS ................................. 103
5.8.7 Testing hypothesis for the case of video monitors in WBS ......................................... 103
5.8.8 Testing hypothesis for the case of video cameras in WBS .......................................... 104
5.9
Research Questions Answered ......................................................................................... 104
5.9.1 Research question 1 ..................................................................................................... 104
SUMMARY AND RECOMMENDATIONS ............................................................................... 112
6.1
Restatement of the Problem ............................................................................................. 112
6.2
Description of Procedures ................................................................................................ 112
6.3
Major Findings ................................................................................................................. 113
6.4
Contribution of the thesis to the field of engineering ...................................................... 114
6.5
Recommendations ............................................................................................................ 114
6.6
Recommendations for Further Investigation ................................................................... 115
BIBLIOGRAPHY .......................................................................................................................... 117
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LIST OF TABLES
Table 1.1:
Equipment reliability as a central factor from the point of view of the television owner, the advertiser, the
viewer and the station employees. ...................................................................................................................... 22
Table 4.1:
Data for video cameras in UTV ................................................................................................................ 75
Table 4.2:
Data for video tape recorders in UTV (Part 1) .......................................................................................... 76
Table 4.3:
Data for video tape recorders in UTV (Part 2) ......................................................................................... 77
Table 4.4:
Data for video monitors in UTV ............................................................................................................... 78
Table 4.5:
Data for video tape recorders in WBS TV ............................................................................................... 80
Table 4.6:
Data for video tape recorders in WBS TV (Part 2) .................................................................................. 80
Table 4.6:
Data for video tape recorders in WBS TV (Part 3) .................................................................................. 81
Table 4.7:
Data for video monitors in WBS TV (Part 1) .......................................................................................... 81
Table 4.8:
Table 4.9:
Table 4.10:
Data for video monitors in WBS TV (Part 4)........................................................................................... 83
Table 4.11:
Data for video monitors in WBS TV (Part 5) ..................................................................................... 83
Table 5.1
Summary of the UTV and WBS maintenance models .............................................................................. 86
Table 5.2
Time between failures (TBF) for 12 video tape recorders for every failure occurrence ........................... 87
Table 5.3
Results of descriptive analysis for values of Time Between failures (TBF) for video tape recorders ..... 87
Table 5.4
Spares used per video tape recorder per year (USD) ................................................................................ 87
Table 5.5
Results of descriptive analysis for cost of spares used per video tape recorder per year .......................... 88
Table 5.6
Time between failures (TBF) for 4 video monitors for every failure occurrence (days) ......................... 88
Table 5.7
Results of descriptive analysis for video monitors: .................................................................................. 88
Table 5.8
Cost of spares used per monitor per year (USD) ...................................................................................... 88
Table 5.9
Descriptive analysis(spares used per monitor per year) ............................................................................ 88
Table 5.10
Calculation of equipment hours of use per day in UTV. ...................................................................... 89
Table 5.11
Summary of results from UTV ........................................................................................................... 89
Table 5.12
TBF values for video tape recorders in WBS (hours) ........................................................................ 90
Table 5.14
TBF values for video monitors in WBS(hours) ................................................................................. 90
Table 5.16
TBF values for video cameras (hours) ................................................................................................. 91
Table 5.18
Cost of spares per year for video tape recorders in WBS (USD) ........................................................ 91
Table 5.21
Summary of results from WBS ............................................................................................................ 93
Table 5.22
Pareto analysis of video tape recorders in UTV .................................................................................. 96
Table 5.23
Pareto analysis of video tape recorders in WBS TV ............................................................................ 96
Table 5.24
Reliability figures from UTV and WBS ........................................................................................... 105
Table 5.25
Most common faults for video tape recorders .................................................................................... 105
Table 5.26
Most common faults for video monitors ............................................................................................ 106
Table 5.27
Most common faults for video cameras ............................................................................................ 107
Table 5.28
Number of days between successive replacements. ........................................................................... 109
Table 5.29
Recommended replacement hours and actual replacement hours in UTV ......................................... 109
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LIST OF FIGURES
Fig.2. Bathtub curve ......................................................................................................................................................... 35
Fig.2.2. Wear out curve .................................................................................................................................................... 35
Fig.2.3 No wear out curve .............................................................................................................................................. 35
Fig.2.4 Low infant mortality curve ................................................................................................................................... 36
Fig. 2.5 Random failure curve .......................................................................................................................................... 36
Fig.2.6 High infant mortality curve .................................................................................................................................. 36
Fig. 2.7 Failure rate of electronic components. ............................................................................................................... 37
Fig.2.8 Pareto diagram in form of a histogram .............................................................................................................. 44
Fig.2.9 Pareto diagram in form of a pie chart ................................................................................................................ 44
Fig.2.8 Organisational chart of UTV up to November 2005 ........................................................................................ 49
Fig. 2.9 Organisational chart of WBS TV ....................................................................................................................... 51
Fig.4.2 UTV stores requisition form............................................................................................................................... 63
Fig. 4.1. UTV Stores withdrawal form ............................................................................................................................. 63
Fig. 4.2. UTV Engineering job card ................................................................................................................................. 64
Fig. 4.5 Tabulation of data obtained in UTV ................................................................................................................... 73
Fig. 4.6 Tabulation of data obtained from WBS TV. ...................................................................................................... 78
Fig 5.1 Cost of spares per machine per year (UTV&WBS) ........................................................................................... 94
Fig 5.2 Equipment MTBF (UTV&WBS) ....................................................................................................................... 94
Fig 5.3 Average wages for maintenance staff................................................................................................................. 94
Fig 5.4 Number of defects for video tape recorders in UTV .......................................................................................... 97
Fig 5.5 Cost of spares for video tape recorders in UTV ................................................................................................... 97
Fig. 5.6 Number of defects for video tape recorders in WBS .......................................................................................... 98
Fig 5.7 Cost of spares for video tape recorders in WBS ................................................................................................ 98
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LIST OF ACRONYMS
AC
Alternating Current
CCD
Charge Coupled Device.
DC
Direct Current
EATV
East Africa Television.
EHT
Extra High Tension.
HOT
Horizontal Output Transistor
IC
Integrated Circuit
LTV
Lighthouse Television.
MTBF
Mean Time Between Failures.
OAU
Organisation of African Unity.
SPSS
Statistical Package for Social Scientists
TBF
Time Between Failures.
TTR
Time To Repair.
UBC
Uganda Broadcasting Corporation.
UHF
Ultra High Frequency.
UPS
Uninterruptible Power Supply.
USHS
Uganda Shillings.
UTV
Uganda Television Service.
VAT
Value Added Tax.
VHS
Video Home System
VTR
Video Tape Recorder.
WBS
Wavah Broadcasting Service.
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LIST OF SYMBOLS
SYMBOL
DESCRIPTION

Failure Rate
T
Period of observation

Mean Time Between Failures (MTBF)
F
Capacitance ( microfarads)
o
Reference value of MTBF
s
Sample standard deviation
n
Sample size
x
Sample mean
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ABSTRACT
Equipment reliability is a more important issue in Africa because of meagre financial resources and
lack of entrepreneurs well versed with the subject. The business entrepreneur is interested in profit,
and the issue of equipment reliability, which affects his production output and hence profit needs to
be addressed.
The research addresses the problems of equipment reliability in TV stations, focusing on television
stations in Uganda. The background of private and public television in Uganda
is given in the
context of equipment reliability versus profit. The objectives of research are stated centring on
reliability and justifying the importance of going into the research of equipment reliability in
television stations.
The development of maintenance records are discussed from a historical perspective culminating in
modern day methods of maintenance records gathering and storage. The different types of failure
models for equipment are outlined. The interrelationship between reliability, observed failure rate
and Mean Time between Failures (MTBF) is mathematically defined. Condition based maintenance
as a modern method for reducing maintenance costs is outlined. Reliability figures from studio
broadcast equipment are stated. The Pareto, Chi squared and two tailed t distribution methods of
failure data analysis are mathematically and graphically described. The contribution of reliability
analysis to engineering is outlined. The gap addressed by the research which is the use of
questionnaires to generate maintenance records is stated. An overview of UTV and WBS is carried
out and recent developments in TV broadcasting technology are outlined.
The geographical area where the research was done and time range of data that was collected is
outlined. Methods of selection of equipment types that were assessed based on quality and quantity
of data that was available are stated.
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The challenges of maintenance in UTV and WBS are presented. The maintenance procedures and
strategies in UTV and WBS are outlined Equipment failure costs are defined. The formats for
tabulation of data in WBS and UTV are explained. The Mean Time between Failures and cost of
spares per machine per year as reliability parameters in the research are mathematically defined.
Finally the data obtained from Job cards in UTV and Questionnaires in WBS together with the
calculated reliability and maintenance cost parameters are presented in a tabular form.
The UTV and WBS maintenance models are discussed. The MTBF and cost of spares per machine
per year for each of the two stations is calculated proving that in both UTV and WBS video tape
recorders are the least reliable and most expensive to maintain whereas video monitors are the most
reliable and cheapest to maintain. Pareto analysis is carried out for failure rates versus spares costs
for video cassette recorders to prove that in the case of UTV 19% of the total number of defects
contributed 59% of the total spares cost whereas in WBS 46% of the total number of defects
contributed 59% of the total spares cost. The cost of spares is plotted against the frequency of
maintenance to determine one cost saving strategy. The hypothesis is tested to with the result that
the alternative hypothesis is therefore upheld i.e. „broadcast equipment used by TV stations in
Uganda are not maintained to the reliability standards of the equipment manufacturers.‟ Finally
research questions on the reliability for each category of equipment in Uganda, equipment purchase
criteria, reduction of maintenance costs and ways of increasing broadcast equipment reliability are
discussed.
The final recommendations are to improve maintenance management in Uganda by including
proper specifications in procurement documents, ensuring proper environment of operation for
equipment, instilling a maintenance culture in Ugandans, timely decommissioning of equipment,
training and proper recruitment of maintenance personnel.
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CHAPTER ONE
INTRODUCTION
1.1
Background
TV stations all over the world invest a lot of money in the purchase and maintenance of broadcast
equipment;
In the NHK (Japan Broadcasting Corporation) annual report for 2008-2009 [1], programme
production and transmission amounted to ¥ 79.9 billion which was 74.2 % of the total expenditure.
587.2 billion was in form of fixed assets . The value of fixed assets increased to ¥ 623.6 billion in
2009-2010 [2]. The increased contribution of fixed assets to the stations investments meant that
there was a need to increase the reliability and efficiency of maintenance regimes to keep the assets
in a productive condition.
The South African Broadcasting Corporation (SABC) annual report for 2006 [3] put the total assets
at 3,307.205 billion Rand. 129 million Rand was spent on depreciation and impairment of plant and
equipment. This cost may have been reduced by improvement of maintenance strategies hence
increased equipment reliability.
The Africa media development initiative‟s 2006 Country report for Uganda [4] cited one of the
specific challenges faced by the TV sector in Uganda as the huge capital cost for investors wanting
to establish TV stations.
Berwanger (1987) [5] states that „The technical facilities for a medium- sized television station,
however lie somewhere within the range of four to eight million US dollars, and about the same
amount is needed for a transmitter network covering at least the urban areas of smaller countries‟ .
The cost per unit for television equipment is high for the following reasons:
16
(i)
Stringent specifications for broadcast equipment lead to inclusion of expensive components
in the production of TV equipment.
(ii)
Television programme production demands stimulate a high turnover in technological
innovations. Customers pay for this high investment in research and development (R&D)
through high prices for television broadcast equipment.
(iii)
The specialized nature of TV programme production and transmission leads to low volumes
of production of television broadcast equipment. This means that the fixed manufacturing
overheads contribute a large portion of the final cost price. This makes the equipment
expensive.
(iv)
Uganda Revenue Authority levies high importation taxes on broadcast equipment. As an
example, one Sony UVW 1800P Betacam editing recorder imported into the country on
1/12/2004 by UTV had an invoice value of 16,380,000/=. It attracted import duty tax
amounting to 2,366,364/= and Value added tax (VAT) amounting to 3,084,161/=
representing a total of 5,450,525/= or 33.3 % tax.
Among the equipment that are critically important in Ugandan TV stations are the ones used in
studios for production of TV programs, postproduction and transmission play out. These include
cameras, video tape recorders (VTR), video monitors, video mixers, sound mixers, linear and nonlinear editing units, video and audio processing equipment. TV broadcasting in Uganda was a state
monopoly until the late 1990‟s when WBS and LTV, as private media players, joined the state run
UTV (New Vision, 1999). Among factors that made this possible were the following:
(i)
Liberalization of the airwaves by government made it possible for private individuals and
organizations to be licensed to operate their own TV stations.
(ii)
There was a realization that TV broadcasting in Uganda was a profitable business. There
was hope that equipment purchased would be reliable. This would enable the money
17
invested to be recouped coupled with a reasonable profit. There was also an unsaturated
market in television advertising. It was therefore possible to adjust advertising rates (cost
price) upwards to cater for programme production, transmission, maintenance, labour costs
and other overhead costs. This flexibility of adjustment of cost price was absent in other
business sectors, where there would be a risk of losing customers to the competition.
(iii)
Mushrooming local firms and multinationals brought about the need for promotion of
products through advertising, and hence television advertising.
(iv)
There was a public demand for better quality television services both in terms of programme
content and reliability of transmission that could not be offered by the state media.
(v)
There were individuals, groups and institutions with a political or sectarian agenda seeking
to get a share of viewers. An example is the group of born again Christians who invested a
lot of money in the setting up of Lighthouse Television (LTV) and Top TV.
(vi)
Some individuals and companies sought to promote their business by having control over
advertising. An example is the promotion of the Wavamunno Empire through advertising on
WBS television. Another example is the Mr. Mengi of Tanzania who owns East Africa TV
(EATV), PULSE TV, ITV and Channel 10.
The overriding motive in all these ventures was profit. Equipment reliability would affect their
capacity to generate profit in the following ways:
(i)
Increased expenditure on maintenance staff wages, spares and purchase of new equipment
would lead to a reduction in the profit margin.
(ii)
They would not be able to give timely service to customers (advertisers) and would
therefore lose them.
(iii)
Production output would be reduced due to a smaller number of equipment in service.
18
(iv)
Their image would be tarnished in the eyes of the viewers and advertisers, who would think
that they possess unreliable equipment. The advertisers would therefore not approach them
or would need to be wooed into doing business with them.
Equipment reliability has been low as evidenced by the numerous transmission hitches on the state
run UTV but also very visible on the private television stations. There was also a sizable quantity of
relatively new equipment lying in the maintenance workshops of private television stations. These
firms, as a result, incurred high maintenance costs and indirect costs related to the reduced
availability of equipment. The low equipment availability for production work resulted in decreased
profits.
The first private TV station in Uganda was Cablesat Television. This station was commissioned in
1992 and wound up in 1997. Its constant breakdowns in transmission could be attributed to low
equipment reliability.
Uganda Television and Radio Uganda in their roles as public broadcasters had their share of
equipment reliability problems. Government funding for these institutions continued to dwindle
over the years. In 1998/1999 financial year, government funding for UTV and radio Uganda stood
at about one billion shillings recurrent expenditure. In 2004/2005 financial years, government
funding for UTV and Radio Uganda stood at about 300 million shillings recurrent expenditure. This
represented a drop of about 70 percent over a six-year period. In spite of this, UTV and Radio
Uganda strived to collect more revenue using meagre resources. For example in 2001/2002
financial year a total of about 468 million shillings was collected and banked with consolidated fund
in the Government of Uganda treasury. In contrast a total of about 864 million shillings was
collected in financial year 2002/2003(Office of the President, 2003). UTV and radio Uganda had no
access to these funds once they were banked and would only depend on the meagre monthly
funding from government. Equipment reliability, therefore, became a key issue because of the lack
19
of money to buy spares and new equipment. The equipment in use was generally older and its
reliability had a direct bearing on its quality of service. Low reliability of equipment meant low
quality service and high reliability of equipment meant high quality service. It is clear that the
dwindling government financing for these institutions resulted in low quality service caused by low
reliability of equipment.
Spanning across the private and public broadcasting sector was the need to study reliability trends
of broadcasting equipment in Uganda (Interviews with WBS and UTV management). A study was
therefore urgently required to look into the causes of low equipment reliability and make
recommendations on ways of increasing it. It was hoped that increased reliability would make these
institutions more profitable in the following ways:
(i)
They would spend less on equipment and spares purchases and therefore realize higher
profits.
(ii)
They would be able to reduce on the number of maintenance staff, which would lead to a
reduction of the wage bill.
(iii)
Reduced downtime would mean higher availability of equipment. Downtime has always
affected the productive capability of physical assets by reducing output, increasing operating
costs and interfering with customer service (Moubray, 1993). Increased reliability of
equipment would therefore result in a higher volume of output thereby higher revenue.
(iv)
Improved quality and volume of production would result in increased viewers and attract
advertisers to the station.
(v)
With low costs it is possible to reduce the advertising rates and attract more business.
Reliability of equipment is cost related and therefore no study can be done into profitability of TV
stations without looking at reliability of equipment.
20
„In recent years the subject of reliability prediction, based on the concept of validly repeatable
component failure rates, has become controversial. First, the extreme wide variability of failure
rates of allegedly identical components under supposedly identical environmental and operating
conditions is now accepted. The apparent precision offered by reliability prediction models is thus
not compatible with the accuracy of the failure rate parameter. As a result, it can be concluded that
simplified assessments of rates and the use of simple models suffice (Smith, 2001).‟ It is on this
basis that this report based its findings on actual failure rate data other than predicted failure rate
data.
From the point of view of a TV station, equipment reliability affects the quality and quantity of
programmes that are aired. If equipment reliability is low, the advertiser, who is the main source of
revenue, will not bring business. As a result, the station‟s earnings will fall with the resultant loss of
profits and failure to meet the station‟s obligations, for example, wages for staff, dividends to
shareholders and so forth. This interwoven relationship between a TV station‟s performance and
equipment reliability is illustrated in table 1.1 below.
The absence of a working document on reliability in the Ugandan broadcasting sector left an
unknown factor, which needed to be investigated and assessed.
It was believed that the research would result into a working document for firms in the broadcasting
sector. It would also be useful for those intending to venture into the broadcasting sector.
21
Table 1.1:
Equipment reliability as a central factor from the point of view of the television
owner, the advertiser, the viewer and the station employees.
TELEVISION
TELEVISION
TELEVISION
TELEVISION
VIEWER
ADVERTISER
OWNER
STATION
EMPLOYEES
Programme
quality (how good are quality
the programmes?

 Profit (Will I stay Wages (how much
Programme
(does
programme Equipment
station‟s
Programme line
the in this business?)
up
fit
my reliability
quantity (how many advertising theme?)
good programmes are Advertising
am I getting paid?)
Equipment
(affects reliability (affects my
station‟s
image, work output and could
rates production output i.e. cause me trouble with
there?)
(Are they fair?)
revenue, spares and my bosses who may
Equipment
Equipment
equipment downtime think
reliability
(How reliability (will my or
equipment inefficient
many times does my adverts play properly replacement
favourite programme at the correct time?)
fail to play or play Viewers
badly?)
attract?)
this
(what General
station e.g.
I
am
and
fire
i.e. me).
Working
costs).
percentage of viewers (costs
does
that
costs conditions (How do
consumables company regulations
tapes.
wages,
Staff and codes of work
taxes, affect
my
freedom
transport and royalties and relationship with
i.e. TV rights)
1.2
other workers?)
Maintenance Regimes
The technology committee at the South African Broadcasting Corporation (SABC) assesses and
evaluates the adequacy of the SABC‟s technology and related systems. It ensures that technology,
management, information systems and relevant controls are up to date, competitive and can cope
22
with planned strategy and also that the SABC utilizes appropriate and innovative technology and
platforms to deliver on its mandate.[3].
With the new information technology, costly and time consuming measuring procedures are no
longer needed for locating individual defective components. The new measuring systems with their
„distributed intelligence‟ locate defective modules (that can then be replaced) in the normal course
of operations.
Measurement and maintenance technology includes process control/automatic test and measurement
devices, automatic insertion test signals, automatic television network monitoring and computer
controlled telemetric systems
The above systems boast a better cost benefit ratio and permit more rational utilisation of technical
operation and production facilities [5].
1.3
The Relationship Between Maintenance, Reliability and Profitability
The Africa media development initiative‟s 2006 Country report for Kenya [6] reported that Radio
stations in Kenya face the challenge of financing, occasioned by the high cost of operations,
relatively small advertising markets and high equipment maintenance costs. This clearly indicated
that the challenges of financing were partly caused by the high equipment maintenance costs. .
Maintenance is the largest single manageable expenditure in the plant: in many companies,
surpassing their annual net profit. Although many agree that maintenance strategies such as
preventative and predictive maintenance programs have been shown to produce saving of up to
25%, studies have shown that still 1/3 of these maintenance cost can be saved. Typically,
maintenance cost can be divided into two main groups. The first group referred as direct costs are
easy to justify and to report. These direct costs consist of items such as labor, materials, services,
23
and maintenance overhead. The other groups of maintenance costs are hidden costs or indirect costs
which are harder to measure. These hidden costs of maintenance are classified as the six big losses:-
1.
Breakdowns and unplanned plant shutdown losses
2.
Excessive set-up, changeovers and adjustments losses
3.
Idling and minor stoppages
4.
Running at reduced speed
5.
Startup losses and
6.
Quality defects
Therefore, it is very important for companies to maximize their maintenance effectiveness and
equipment uptime. According to a study on maintenance productivity, most maintenance
departments are only around 25% to 35% productive. This causes many companies to experience
difficulties with quality control, production levels and schedule adherence, since the equipment they
are using is not properly maintained [7].
1.4
Statement of the Problem
TV stations in Uganda invest a lot of money in the purchase of modern broadcast equipment. Visits
were carried out to both UTV and WBS and it was noted that there was a high number of
equipment that were defective. This was adversely affecting the transmission quality and capacity
of the TV stations in terms of programmes that could be transmitted with good quality, and quantity
of equipment that were available for production work, that is, recording and editing of programmes.
It was therefore considered necessary to assess the reliability of equipment used in both stations in
order address the following problems:
(i)
Rapid deterioration of equipment due to lack of maintenance schedules.
24
(ii)
Frequent breakdowns caused by the absence of procedures for increasing the reliability of
equipment.
(iii)
High maintenance costs. Maintenance costs include maintenance staff wages, costs of spares
and equipment downtime costs. Maintenance costs are considered important as they
contribute a significant percentage to the total costs of running a TV station.
(iv)
Absence of a procedure to assess reliability in order to enhance lifespan and predictability of
failure rates. An increase in lifespan is considered important as it would spread out the
incidents of major capital investment.
To illustrate this point, the cost of a typical professional Video tape recorder (VTR) is about 10000
USD (18 million Ushs) . The cost of replacement of ten VTRs typically used in a TV station would
be 180 million Ushs.
1.5
General Objective
To assess the reliability of various categories of broadcast equipment in Uganda television
stations.
1.6
Specific Objectives
(i)
Assessing the reliability of broadcast equipment in Uganda television stations using
historical data and questionnaires.
(ii)
Using reliability data to draw conclusions about the best maintenance strategy for each
category of equipment.
(iii)
Finding causes of the most commonly occurring faults.
25
1.7
Significance of the Problem
Berwanger (1987)[5] states that „the percentage of expenditure on spare parts and consumable
goods seems to lie between 5% and 12% of the budget of a station according to the findings of the
author in a number of television stations in Africa and Asia.‟
In 2005 Uganda Television and Radio Uganda had a total of 234 staff out of which 86 were
technical staff. It can therefore reasonably be said that 37 % of the wage bill was meant to cater for
the maintenance cost. As a contrast WBS television had a total of 120 staff out of which 10 were
technical staff. In this case WBS, only 8% of the wage bill was meant to cater for the maintenance
cost.
In the context of research on equipment reliability we shall define the following to constitute
maintenance costs:
(i)
Cost of spare parts.
(ii)
Cost of paying wages to maintenance staff.
Since there were many pieces of equipment that were out of order, it was felt that the equipment
was not reliably maintained; yet this was the only way that the TV station owners could get out of
their predicament. Solutions to maintenance practices had to be found that would lead to less
equipment being out of service while also reducing maintenance costs;
The research was therefore undertaken to into the engineering aspects of maintenance of equipment
at UTV and WBS to assess failure rates, maintenance activities and physical maintenance models.
Mathematical methods were also used to assess reliability.
The situation in Africa has the following unique characteristics that impact on the way the issues of
cost of spare parts and maintenance staff have to be addressed:
1.
Broadcast equipment manufacturers are based outside Africa. It is therefore not possible to
implement the „Just in time‟ delivery of spare parts. Spare parts therefore have to be stocked.
26
Overstocking caused by wrong reliability predictions causes inefficiencies. On the other
hand, under stocking again caused by wrong reliability predictions will lead to a drop in
production. In the former case the station will incur unjustifiable costs of depreciation and
eventual obsolescence of the spare parts. In the latter case there will be indirect costs caused
by loss of production capacity.
2.
Repair and service by the factory maintenance engineer is both expensive and difficult to
implement. In some cases it may be possible to subcontract the maintenance of equipment
depending on the cost of service and availability of skilled firms within the country or
region. However, in most cases TV stations in Africa have to rely on their maintenance
personnel to solve the equipment reliability and maintenance problems. This is mainly due
to the absence of skilled firms coupled with the direct and indirect costs of being dependent
on another organisation. The maintenance personnel are ill equipped to handle the issue of
reliability because they do not participate in the initial design stages of the equipment and
they don‟t possess local reliability data. The costs resulting from this are due to employment
of a large maintenance workforce, and indirect costs of increased equipment downtime
caused by lack of reliability data. Indeed Berwanger(1987) states that “the managements of
many television stations in the third world openly admit that while there is not enough
qualified personnel, the number of employees is at least three or four times higher than that
objectively needed”.
It is clear that there are several ways to maximize profits, amongst which are:
(i)
Increased sales (revenue) by increasing the reliability of the equipment. Increasing the
reliability of the equipment will lead to its increased availability for production, hence
increased sales (revenue).
27
(ii)
Increased reliability of the equipment by use of cost effective, efficient maintenance
methods, by adoption of a suitable maintenance strategy will lead to a reduction in
maintenance staff costs and spare parts costs and hence an increase in profits.
This research therefore focused on analysing the reliability data obtained , finding out the factors
causing such figures, comparing the results with similar research , recommending methods of
improving on reliability as a way of increasing availability (thereby increasing production and
revenue) and reduction of costs directly and indirectly related to equipment downtime and
maintenance costs.
The overall aim of the research was to come out with recommendations that once adopted by TV
stations would lead to improved equipment reliability. This in turn would lead to higher profitability
for the stations and better transmission quality for the Ugandan public.
1.8
Scope of Research
The research covered three categories of equipment, namely, video monitors, video tape recorders,
and video cameras. These categories of equipment were chosen because of their sufficient numbers
in each of the TV stations and hence amenable to statistical analysis and calculation.
1.9
Choice of TV stations
At the time of research only UTV, WBS, Lighthouse Television and Channel television had TV
studio facilities. An attempt was made to go to Lighthouse Television but management turned down
the request to carry out research at their facility. Channel television studios at Nakigalala hill were
inaccessible due to instructions from Management. However management of UTV and WBS agreed
to allow the research to be carried out at their facilities.
28
The research involved equipment serviced in UTV workshop between 1997 and 2005and equipment
serviced in WBS workshop between 1999 and 2005. 1.10
For an accurate calculation of reliability, the following data was required:
1.11
(i)
Category of Equipment (video tape recorder, video camera, video monitor)
(ii)
Date of failure.
(iii)
Date of repair.
(iv)
Frequency of repair (to replace date of failure and date of repair).
(v)
Spares needed for repair.
(vi)
Cost of spares.
(vii)
Type and frequency of maintenance carried out.
Statement of Hypothesis
1.11.1 Alternative hypothesis:
Broadcast equipment used by TV stations in Uganda are not maintained to the reliability
standards of the equipment manufacturers.
1.11.2 Null hypothesis:
Broadcast equipment used by TV stations in Uganda are maintained to the reliability
standards of the equipment manufacturers.
1.12
Assumptions
The following assumptions were made in UTV:
a)
That failure data gathered on twelve professional video tape recorders was a representative
sample of all video tape recorders.
29
b)
That failure data gathered on four professional video monitors was a representative sample
of all video monitors.
c)
That failure data gathered on two professional video cameras was a representative sample of
all video cameras.
d)
That data gathered in UTV was reliable this was because the Job cards used were properly
filled out by maintenance staff and the central workshop was the only location for repair of
studio equipment.
e)
That data gathered in WBS was reliable since the quantity of information gathered on a large
quantity of equipment would compensate for errors in human recollection of events.
1.13
Research Questions
The following were identified as questions to be answered:
1.
What is the reliability for each category of equipment in Uganda and how does it compare
with reliability figures from equipment manufacturers?
2.
Which equipment purchase criteria should be used to tackle the issue of intrinsic, or
inherent, reliability?
3.
How can maintenance costs be reduced without adversely affecting reliability?
4.
How can broadcast equipment reliability be increased?
5.
Was the equipment properly maintained? Details of spare parts that were replaced were
compared with the manufacturers‟ specified periodic preventive maintenance schedules.
6.
How did the component failure models follow theoretical component failure models, for
example the pareto law? Theoretical component failure models were investigated.
7.
What were the maintenance models for UTV and WBS? A connection between the
maintenance models, the breakdown of the equipment and the cost of repair was
30
investigated.
8.
What maintenance practices in UTV and WBS would lead to a saving of cost and the
estimated amount of money that would be saved as a result of adopting them?
1.14
Limitations
The following were limitations in UTV:

Written records (job cards) were only available for items that had been repaired in the
central workshop. It was found that very little repair work was carried out outside the
workshop. This limitation would therefore not adversely affect the accuracy of findings.
The following were limitations in WBS TV:

The technical staff‟s depth of recollection of failure data was a factor that would affect the
accuracy of the research. Fortunately there were some written records that helped the staff to
give a more accurate account. Some of the records consulted were the data book, the fault
report book and the stores requisition book.
31
CHAPTER TWO:
REVIEW OF RELATED LITERATURE
2.1
Introduction
In this chapter the development of maintenance records are discussed from a historical perspective
culminating in modern day methods of maintenance records gathering and storage. The different
types of failure models for equipment are outlined. Equipment reliability is defined from different
perspectives. The interrelationship between reliability, observed failure rate and Mean Time
between Failures (MTBF) is mathematically defined. Condition based maintenance as a modern
method for reducing maintenance costs is outlined. Reliability figures from studio broadcast
equipment are stated. The Pareto, Chi squared and two tailed t distribution methods of failure data
analysis are mathematically and graphically described. The contribution of reliability analysis to
engineering is outlined. The gap addressed by the research which is the use of questionnaires to
generate maintenance records is stated. An overview of UTV and WBS is carried out and recent
developments in TV broadcasting technology are outlined.
2.2
The Development of Maintenance Records:
Maintenance disciplines and keeping of maintenance records have evolved through three
generations. First generation equipment (1930 –1940) was over designed and consequences of
failure were not severe. They were less severely constrained by the cost and schedule pressures of
today. In many cases high levels of reliability were achieved as a result of over design. The
equipment was also easy to repair because of its simplicity. There was no need for systematic
maintenance of any sort beyond simple cleaning, servicing and lubrication routines. The need for
quantified reliability assessment during design, development and use was therefore not identified.
32
Therefore failure rates of engineered components were not required, as they are today, for use in
prediction techniques and consequently there was little incentive for the collection of data. Industry
was not highly mechanised, so downtime did not matter much. This meant that the prevention of
equipment failure was not a very high priority in the minds of most managers. Another factor is that
component parts were individually fabricated in a „craft‟ environment. Mass production and the
attendant need for component standardisation did not apply and the component of a valid repeatable
component failure rate could not exist. The reliability of each product was, therefore, highly
dependent on the craftsman/manufacturer and less determined by the „combination‟ of part
assemblies. A “fix it when it breaks” maintenance approach was generally adopted.
Second generation equipment (1940 – 1970) became more complex, there was less manpower and
demand for goods and services increased. This led to increased mechanisation. By the 1950‟s
machines of all types were more numerous and more complex. Industry began to depend on them.
As this dependence grew, downtime came into sharper focus. This led to the idea that equipment
failures could and should be prevented, which in turn led to the concept of preventive Maintenance.
In the 1960‟s this consisted mainly of equipment overhauls done at fixed intervals. The cost of
maintenance also started to rise sharply relatively to other operating costs. This led to the growth of
maintenance planning and control systems. The amount of capital tied up in fixed assets together
with a sharp increase in the cost of that capital led people to start seeking ways in which they could
maximise the life of the assets. Mass production of standard mechanical parts meant that defective
items could be identified readily by means of inspection and test, during the manufacturing process
and it was therefore possible to control reliability by quality control procedures. The advent of the
electronic age accelerated by the second world war, led to the need for more complex massproduced component parts with a higher degree of variability in the parameters and dimensions
involved .The experience of poor field reliability of military equipment throughout the 1940s and
33
1950s focused attention on the need for more formal methods of reliability engineering. This gave
rise to the collection of failure information from both the field and from the interpretation of test
data. Failure rate data banks were created in the mid 1960s as a result of work at such organisations
as UKAEA (UK Atomic Energy Authority) and RRE (Royal Radar Establishment, UK) and RADC
(Rome Air Development US).
The manipulation of data was manual and involved the calculation of rates from the incident data,
inventories of component types and the records of elapsed hours. This activity was stimulated by
the appearance of reliability prediction modelling techniques which require component failure rates
as inputs to the prediction equations.
Third generation equipment (1970 – Date) became even more complex. Equipment cost
effectiveness; competitiveness, downtime costs, reliability, availability and equipment lifetime
became critical issues. New maintenance techniques such as condition monitoring were adopted.
Greater automation also means that more and more failure affect our ability to sustain satisfactory
quality standards. At the same time as the dependence on physical assets is growing, so too is their
cost to operate and to own. To secure maximum return on the investment which they represent, they
must be kept working efficiently for as long as they are needed to. The cost of maintenance is still
rising in absolute terms as a proportion of total expenditure. The availability and low cost of
desktop personal computing (PC) facilities, together with versatile and powerful software packages,
has permitted the listing and manipulation of incident data for an order less expenditure of working
hours. Fast automatic sorting of data encourages the analysis of failures into failure modes. This is
no small factor in contributing to the more effective reliability assessment, since generic failure
rates permit only parts count reliability predictions. In order to address specific system failures it is
necessary to input component failure modes into the fault tree or failure mode analyses.
34
The labour intensive feature of data collection is the requirement for field recording which remains
a major obstacle to complete and accurate information. Motivation of staff to provide field reports
with sufficient detail is a current management problem. The spread of PC facilities in this area have
assisted to the extent that interactive software can be used to stimulate the required information
input at the same time as other maintenance logging activities.
With the rapid growth of built-in test and diagnostic features in equipment the trend is the
emergence of some limited automated fault reporting.
New research has changed many beliefs about age and failure. Third generation research has
revealed that not one or two but six failure patterns actually occur in practice:
Probability of failure
Time
Fig.2.1.
Bathtub curve
Time
Fig.2.2.
Wear out curve
Time
Fig.2.3.
No wear out curve
35
Time
Fig.2.4.
Low infant mortality curve
Time
Fig. 2.5.
Random failure curve
Time
Fig.2.6.
High infant mortality curve
Bathtub Curve: has a run in period followed by a steady wear period. This pattern is
characteristic of electromechanical (classical) equipment.
36
Final wear out curve: shows a constant or gradually increasing probability of failure. This is a
characteristic of simple mechanical over designed equipment.
No wear out curve: shows a failure probability, which is slowly increasing but without a
defined wear out stage.
Low infant mortality curve: Failure probability is low during the infancy stage but after that
assumes a constant level.
Random failure curve: failure probability is constant through out the age of the equipment.
This behaviour is characteristic of software controlled and IT equipment e.g. computers.
High infant mortality curve: Illustrates a high failure probability during the infancy stages of
the equipment (Lakshminarayanan, 2001)[8].This is typical of aircraft because of their extreme
complexity and also because of the intensive nature of preventive maintenance component
replacements.
In general the more complex the equipment becomes the more the pattern evolves downwards from
Fig. 2.1 to Fig. 2.6. (electronic, hydraulic and pneumatic equipment).
Overall, typical failure rate behaviour of electronic components follows a distribution known as the
bathtub curve.
Fig. 2.7.
Failure rate of electronic components.
37
1.
An infant mortality early life phase is characterized by a decreasing failure rate (Phase 1).
Failure occurrence during this period is not random in time but rather the result of
substandard components with gross defects and the lack of adequate controls in the
manufacturing process. Parts fail at a high but decreasing rate.
2.
During the useful life period, electronics have a relatively constant failure rate caused by
randomly occurring defects and stresses (Phase 2). This corresponds to a normal wear and
tear period where failures are caused by unexpected and sudden overstress conditions. Most
reliability analyses pertaining to electronic systems are concerned with lowering the failure
frequency (i.e.,  const shown in Figure 2.7) during this period.
3.
In the wear-out period, the failure rate increases due to critical parts wearing out (Phase 3).
As they wear out, it takes less stress to cause failure, and the overall system failure rate
increases; accordingly, failures do not occur randomly in time.
Failure analysis can give valuable insight into the causes of failure and provide inputs for
productive improvements. It is also a tool for equipment reliability evaluation. Analytical
techniques such as the „Weibull‟ distribution can be used to classify the failure pattern. (Smith,
2001)[9].
2.2.1 Definition of Reliability
Shepherd.J. et.al. (1972)[10] states “Reliability is the characteristic of a component or of a system
which may be expressed by the probability that it will perform a required function under stated
conditions for a specified period of time”.
Cluley.J.C. (1981) [11] defines reliability as “the probability that the system will operate to an
agreed level of performance for a specified period, subject to specified environmental conditions”.
Kawauchi and Rausand (1999) [12] state that reliability is the probability that an item can perform a
required function under given conditions for a given time interval.
38
According to Smith (2001) [9] Quality is the conformance to specification, whereas reliability is
the probability that an item will perform a required function, under stated conditions, for a stated
period of time. Reliability is therefore the extension of quality into the time domain and may be
paraphrased as „the probability of non- failure in a given period‟.
The US military standard MIL – STD – 721C (Smith, 2001) gives two definitions for reliability:
a)
The duration or probability of failure free performance under stated conditions.
b)
The probability that an item can perform its intended function for a specified interval under
stated conditions.
2.2.2 Definition of observed failure rate:
For a stated period in the life of an item, this is the ratio of total number of failures
to the total
cumulative observed time T. If  is the failure rate of N items then the observed  is given by
 
k
, where k is the number of items that have failed.
T
2.2.3 Definition of the observed mean time between failures:
For a stated period of life of an item, this is the ratio of cumulative time to the total number of
failures (in hours). This is
T
…………………………………………………………………...........................2.1
k
2.2.4 Inter relationship of terms:
 (t )
is the failure rate.
f (t )
is the failure probability density function.
R (t )
is the probability of survival to time t, i.e. the reliability. It can be shown that
R (t )
= exp[
t
    t  dt ]
………………………………………………...................2.2
0
39
(Smith, 2001) [9].
If the failure rate is now assumed to be constant
R (t ) 
 t
e
………………………………………………………………...…2.3
It can be shown that the mean life between failures, MTBF will be given by

 
 R ( t ) dt
……………………………………………………………… …2.4
0
In the special case of constant failure rate
 
1

…………………………………………………………………...2.5
(Smith, 2001) [9].
During the research the values of MTBF were normalised to units of hours.
2.3
Factors that Affect Equipment Reliability
Equipment reliability in general is ensured by positively addressing the following factors:

Lack of a periodic check and maintenance schedule or preventive maintenance schedule.
Sony (1989 & 1993) [13] outlines a clear preventive maintenance schedule for their type
„BVU 950P Umatic SP‟ and type UVW 1800 Beta cam SP professional videocassette
recorders.

Environmental stresses such as temperature, shock, vibration, humidity and ingress of
foreign bodies (Smith, 1988) [14].

Self generated stress such as power dissipation, applied voltage and current; self generated
vibration and wear (Smith, 1988) [14].

Intrinsic reliability inherent in the design and manufacture of the equipment caused by level
of complexity, tolerance and stress margins.
40
Preventive maintenance schedules are not always strictly followed due to the following
factors:

Lack of properly trained personnel.

Very little funds are allocated for the maintenance function (including timely acquisition of
spare parts)
The above factors may lead to a high rate of wear and tear resulting into an increase in the
frequency of breakdowns and therefore decreased reliability of equipment
.
2.4
Condition Based Maintenance
Condition based maintenance has been described as a process that requires technologies and people
skills that integrates all available equipment condition indicators (diagnostic and performance data,
operator logged data, maintenance histories, and design knowledge) to make timely decisions about
maintenance requirements of important equipment. Condition based maintenance assumes that
equipment failure modes will follow one or more of the classical degradation styles and that there is
sufficient local knowledge of the equipment‟s historical performance to perform an extrapolation of
its remaining life. This in itself is a form of prognostics based partially on science, and partially on
elicited experience of the plant staff. These measurement techniques, observations, tests, and
operator intuitions are what forms the plant‟s condition based maintenance programme.
The primary objectives of an optimized maintenance strategy programme that include predictive
and condition based maintenance are:
1.
Improve availability
2.
Reduced forced outages
3.
Improve reliability
4.
Enhance Equipment Life
41
5.
Reduce wear from frequent rebuilding
6.
Minimize potential for problems in disassembly and reassembly
7.
Detect problems as they occur
8.
Save Maintenance Costs
9.
Reduced repair costs [17]
2.5
Research on Reliability of TV Studio Broadcast Equipment
Research into the reliability of studio equipment has always involved the manufacturers carrying
out reliability tests prior to mass production. Reliability prediction also comes in the form of
preventive replacement schedules for key components within the respective pieces of equipment.
For analogue video tape recorders, the MTBF value is 1,000 hours, which corresponds to the
replacement time for the video head drum. „Sony broadcast and professional‟ quotes this value for
its range of studio video tape recorders , for example, The Umatic SP BVU 950P, VO 9850P,
Betacam SP UVW 1800P and BVW- 75 P . TEAC Aerospace Technologies (2004) also quote an
MTBF of 1,000 hours for its Hi 8mm airborne video tape recorder.
For video cameras, the MTBF was 750- 1000 hours during the days when picture tubes (for
example, saticon) were used for capturing the image. This means that the picture tubes had to be
replaced every approximately 1,000 hours. The advent of the CCD (charge coupled device) in the
late 1980‟s to replace the picture tube greatly raised the reliability of broadcast cameras. Sony
electronics (2004) quotes an MTBF of 38,200 hours for its 1/3-inch CCD colour camera model XC
777A.
Reliability of video monitors has always been based on quality of solder used. The construction
video monitors with extra high tension (EHT) circuitry and heating due to high currents leads to
42
degradation of the solder. Recent reliability research in U.S.A. (deer2project, 2002) indicated the
MTBF for video monitors to be 10,000 hours.
2.6
Methods of Analysis of Failure Data
2.6.1 Pareto Analysis
Pareto analysis, sometimes referred to as the 80/20 rule and as ABC analysis, is a method of
classifying items, events or activities according to their relative importance. It is used in inventory
management where it is used to classify stock items into groups based on the total annual
expenditure for, or total stockholding cost of, each item. Organisations can then concentrate more
detailed attention on the high value/important items. Pareto analysis is used to arrive at this
prioritisation.
In the specific case of spares usage, important factors to be considered are the categorisation of
defects and their contribution towards the total spares cost. Attention is then focused on those
defects that attract the highest spares cost. Direct application of Pareto law in this case would mean
that 20% of the defects result into 80% of the spares cost. Popular representations of pareto analysis
are the histogram and the pie chart. Both are used to graphically summarize and display the relative
importance of the differences between groups of data. In the case of categorisation of defects, the
histogram is constructed with the vertical bars representing the frequency of occurrence of the user
defined groups of defects. The bars are ordered in descending frequency magnitude .The left-side
vertical axis of the pareto chart is labelled „Frequency‟ (the number of counts for each category), the
right-side vertical axis of the pareto chart is the cumulative percentage, and the horizontal axis of
the pareto chart is labelled with the group names of the user selected response variables .A typical
histogram is shown below:
43
100
100%
90%
80%
70%
Frequency
80
60
60%
50%
40%
30%
20%
10%
40
20
Group
A
Fig.2.8.
Group
B
Group
C
Group
D
Group
E
Pareto diagram in form of a histogram
The pie chart is constructed with the pies representing the percentage contribution of the frequency
of the group to the sum of all frequencies from individual groups. A typical pie chart is shown
below:
Group
B
Group A
Group
C
Group
D
Fig.2.9.
Pareto diagram in form of a pie chart
44
2.6.2 The Chi Square Test
The 
2
1.
T (accumulated test hours ) and k (number of failures) are measured.
2.
A confidence level is selected and
3.
let n=2k (2k +2 for lower limit MTBF in a time truncated test)
4.
the value of  obtained from tables.
5.
let MTBF at the given confidence level be 2T/ 
6.
for double sided limits the above procedure is used twice at
table are used to interpret results of reliability tests as follows:

= (1 – confidence level)
2
n= 2k : 1 -

(upper limit MTBF)...........................................................................2.6.2.1
2
n= 2k(2k + 2) :
2

2
(lower limit MTBF)....................................................................2.6.2.2
The above analysis is also used to prove whether the analysed equipment performance falls within
reliability parameters set by the equipment manufacturer. This test however does not take care of the
variations in TBF (Time between failure) values and was not found suitable for producing an
accurate value of MTBF using the varying data presented in the research.
2.6.3 Two tailed t distribution
The values of TBF (Time Between Failures) for a particular type of equipment can be compared
with a nominal value of MTBF for example the MTBF value from the manufacturer, to prove
whether the value of the observed MTBF falls within statistically acceptable limits.
The acceptable upper and lower values of MTBF are given by;
x
+ t 1 s
.................................................................................................2.5.3
2
n
where n is the sample size of TBF values collected, s is the sample standard deviation,
45
x
is the
sample mean, t 1   is the value from the t distribution with n-1 degrees of freedom that
2
corresponds to

the confidence interval specified.
The nominal value of MTBF (  ) from the manufacturer is compared with the acceptable upper
0
and lower values of MTBF obtained from failure data and calculated as above.
The above analysis is used to prove whether the analysed equipment performance falls within
reliability parameters set by the equipment manufacturer. This serves to mathematically establish
whether equipment is maintained to a reliable standard set by the manufacturer.
2.7
Contribution of Reliability Analysis to Engineering
Reliability Engineering consists of the systematic application of time-honored engineering
principles and techniques throughout a product lifecycle. The goal of reliability engineering is to
evaluate the inherent reliability of a product or process and pinpoint potential areas for reliability
improvement. Realistically, all failures cannot be eliminated from a design, so another goal of
reliability engineering is to identify the most likely failures and then identify appropriate actions to
mitigate the effects of those failures.
In Uganda no reliability evaluation of broadcast equipment has taken place yet the most
important contribution of engineering to the broadcasting sector is to ensure that equipment
correctly perform their intended function in the most efficient and cost effective way possible.
The contribution of this research therefore was to assist engineers in the broadcast industry to adopt
engineering practices and put in place measures to ensure that expensive broadcast equipment
continuously perform their function in the most cost efficient and productive way.
46
2.8
The Gap
During the research, it was envisaged that there would be some difficulty in obtaining
maintenance records in their written form (i.e. job cards and so forth). Other methods of obtaining
maintenance data were planned. The method that was planned to be used was the use of a
questionnaire. The questionnaire would be designed to be answered by personnel in broadcasting
stations where it was found that written maintenance records were lacking or inadequate. The
maintenance data derived from the questionnaire was to be used to supplement the written records
where available. The quality of the data collected would depend on the individual‟s recollection of
frequency and type of failures of the pieces of equipment in question. This innovative approach was
identified as the gap in collection of maintenance records .This is especially true in Africa as very
few broadcasting stations were expected to possess maintenance records of their equipment.
2.9
Overview of Uganda Television
Uganda television service was started in 1963 transmitting in black and white (monochrome). Its
mandate was to inform, educate and entertain. General Idi Amin introduced colour television in
1975 just in time for the 1975 OAU conference.
The infrastructure of a complex studio system, numerous transmitting stations and terrestrial
microwave and UHF programme links was rapidly destroyed by the many wars, neglect and general
economic decline. Intellectual flight also meant that the quality of programming declined. For many
years Uganda television was under the Ministry of Information and Broadcasting. However in 1998
the ministry was absorbed as a department in the Office of the President. An attempt was made to
rehabilitate some of the infrastructure. As a result Uganda Television obtained a state of the art
digital satellite uplink station, which was a relay between the signal source at the Nakasero studios
and the ten (10) TV transmitting stations countrywide.
47
From 2001 Uganda Television and Radio Uganda operated as a directorate within office of the
president with a „Director broadcasting‟ as the head an accountant.
The mandate of Uganda Television was to inform, educate, entertain, mobilize and collect revenue
for government.
The „Uganda Broadcasting Corporation Act 2005‟ was passed by Parliament and gazetted on 20th
May 2005. The Act aimed to replace the State owned and funded Radio Uganda and Uganda
Television with a 100% owned, self sustaining public Broadcasting Corporation. A tentative
transfer date was set for 1st October 2005.One of the immediate functions of the corporation was to
„acquire and apply modern broadcasting equipment and design good organisation structure and put
in place skilled and responsive personnel in line with technology improvements‟. This, and another
function that was „to achieve and sustain reliable signals‟ emphasised the importance of equipment
reliability as a launch pad of the corporation‟s activities.
The mission was to maintain a self-sustaining, high quality-broadcasting corporation that meets the
development expectations of the public.
The figure below shows the organisational chart of UTV before the advent of UBC
48
MINISTER
SECRETARY
PRESIDENT‟S OFFICE
DIRECTOR
BROADCASTING
COMMISSIONER
ENGINEERING
COMMISIONER TV
Chief news
editor
Controller of
programmes
Editors
Heads of
department
Chief commercial
manager
Principal
engineer
Project manager
Senior
Engineers
Producers
Engineers
Reporters
Copy typists
Presenters,
cameramen
Fig.2.8.
commercial
assistants
Technicians
Organisational chart of UTV up to November 2005
UTV and Radio Uganda were transformed into UBC (Uganda broadcasting Corporation) by act of
Parliament in November 2005.
49
2.10
Overview of WBS TV
WBS TV, which is transmitted on channel 25 UHF for the greater Kampala geographical area was
officially launched in 1998. It was therefore among the first
commercial privately owned
television stations in Uganda. It currently has repeaters in Masaka , Mbarara , Jinja and Tororo.
WBS television Ltd is a private limited company under the Uganda companies Act.
The mission of WBS TV is to be the viewers most entertaining, educative and favourite television
station in the east and central region of Africa.
Its objectives include the following:

To entertain, inform and promote religious, cultural, environmental and political awareness
as well as social development and responsibility.

To provide professional, local, qualitatively produced programmes with a blend of highly
entertaining imported programmes for viewers.

To give Ugandans what they want by being professional, inventive, creative and service
minded at all times.

To provide quality, accurate, balanced, non biased extensive in depth news to viewers.

To develop and promote local talent through qualitative production of local programmes in
the form of drama, music, documentaries and magazines.

To raise the standards of advertising in the country by producing quality commercials [8].
WBS is aiming to reach more viewers by providing an upbeat and different mode of programming
as a fresh way of enjoying television. It plans to completely move from analogue to digital
transmission and distribute its signal to upcountry transmitters by satellite, thereby covering the
whole country.
50
WBS Television is headed by a Board of Directors ,a chairman ( Mr. Gordon Wavamunno ) an
executive Managing Director ( Mr. Elvis Ssekyanzi) and a General Manager (Mr. Kazooba). It has a
total workforce of 120 staff.
The figure below shows the organisational chart of WBS TV:
Board of Directors
Chairman
General Manager
Human resource
Manager
Production
Manager
Head of
News
Reporters
Finance
Manager
Head of
programming
Accou
ntant
Producers
Cashier
Station
Manager
Public
relations
officer
Chief
Technician
Senior
technicians
Technicians
News
readers
Presenters
Fig. 2.9.
2.11
Technical
operators
Organisational chart of WBS TV
Spares Purchase Policies
There was a variance in the spares purchase policies for UTV and WBS. UTV being part of a
department in Presidents‟ office was subject to Public Procurement and Disposal of Assets authority
(PPDA) regulations. This ranged from simple request for quotations (RFQ) for small orders ,where
51
a minimum of three companies were required to bid and subsequently go through the rigours of
technical evaluation and contracts committee approval, to international bidding for large orders
stretching over several months. In WBS spares procurements were almost exclusively handled by
the chairman and this was often done on many of his trips abroad. This not only resulted in purchase
of cheaper spare parts in some instances, but also shortened the time between spares requirement
and delivery. The different spares purchase policies affected the maintenance regime at both TV
stations; UTV used a method of spares requirements prediction to compensate for the long spares
procurement period and thereby overstocked most of the spare parts, whereas WBS practiced a just
in time delivery of spare parts due to a faster procurement time.
2.12
Recent Developments in Television Broadcasting Technology
The world has recently under gone a change from analogue television to digital television.Digital
television (DTV), is a technology that uses digital signals to transmit television programs. Digital
signals consist of pieces of simple electronic code that can carry more information than
conventional analog signals. This code allows for the transmission of better quality sound and
higher resolution pictures, often referred to as high-definition television (HDTV). For example in
United States of America, beginning in 2009, FCC regulations required all stations to turn off their
analog signals and broadcast only in digital.
The transition to HDTV broadcasting has accelerated the conversion of other aspects of television
production from analog to digital. Many stations have replaced specialized hardware with less
specialized computers equipped with software that performs the same functions. Stations are
beginning to switch away from tapes and instead use digital recording devices. This way footage
can be more easily transferred to a computer for editing and storage. Many major network shows
now use HDTV cameras and editing equipment as well.
52
The transition to digital broadcasting also is occurring in radio. Most stations already store music,
edit clips, and broadcast their analog signals with digital equipment. Satellite radio services, which
offer more than 100 channels of digital sound, operate on a subscription basis, like pay television
services. To compete, some radio stations are embedding a digital signal into their analog signals.
With a specially equipped radio, these digital services offer better quality sound and display some
limited text, such as the title of the song and the artist [16]
53
CHAPTER THREE
METHODOLOGY
3.1
Study Area
All the research was conducted in the Kampala area .It was specifically conducted within the
premises of UTV and WBS TV.
3.2
Choice of Sampling Elements in UTV
Most of the equipment found in the UTV workshop records was relatively old. The following
pieces were found to be the newest, and also with sufficient historical data to enable reliability
analysis:
3.2.1
Video Tape Recorders:
The video tape recorders chosen for the research were the Sony BVU 950P Umatic SP , Sony VO
9850P Umatic SP and Sony VO 9800P Umatic SP professional video tape recorders for the
following reasons:

There were many recorders of this type in UTV.

It had sufficient maintenance data to enable reliability analysis.

When they were bought, UTV stocked enough spares both in quantity and variety, for
this model, thereby leading to collection of data on spares usage and cost of spares.
3.2.2
Video Monitors:
The video monitor chosen for the research was the Sony PVM 1442 professional video monitor for
the following reasons:

There were many monitors of this type in UTV.

It had sufficient maintenance data to enable reliability analysis.
54

When they were bought, UTV stocked enough spares both in quantity and variety, for
this model, thereby leading to collection of data on spares usage and cost of spares.
3.2.3
Video Cameras:
The video camera chosen for the research was the Sony DXC 3000P 3CCD colour camera for the
following reasons:

It employs the latest 3CCD (charge coupled device) technology and is therefore
comparable to any state of the art professional camera.
The following is the summary of equipment assessed:
Table 3.1: Video Tape Recorders at UTV
Manufacturer
Sony
Sony
Sony
Model No.
BVU950P Umatic SP recorder
VO9800P Umatic SP recorder
VO9850P Umatic SP recorder
Quantity
6
2
4
Table 3.2: Video monitors at UTV
Manufacturer
Sony
Model No.
PVM 1442 QM video monitor
Quantity
4
Table 3.3: Video Cameras at UTV
Manufacturer
Sony
3.3
Model No.
DXC 3000AP video camera
Quantity
2
Choice of Sampling Elements in WBS TV
In WBS TV the sampled population were all the video tape recorders, all the video cameras and all
the video monitors used within the studio premises. This was done in order to obtain more accurate
55
findings since a questionnaire and interviews were mostly employed. The following equipment was
assessed:
Table 3.4: Video tape recorders at WBS TV
Manufacturer
Sony
Sony
Panasonic
JVC
Sony
Model No.
BVW 75P Betacam recorder
PVW 2800P Betacam recorder
DVC-PRO AJ-D750 DVC PRO recorder
DV/VHS recorder
UVW 1800P Betacam recorder
Quantity
1
5
1
6
6
Table 3.5: Video monitors at WBS TV
Manufacturer
JVC
Sony
Vista
Melford
Philips
Model No.
TM –150 PSNK
PVM 91CE
TVM9B
DU 6 –20C
LHD 6200
Quantity
2
12
4
10
1
Table 3.6: Video cameras at WBS TV
Manufacturer
Sony
Panasonic
Sony
JVC
Model No.
DSR – PD150P DVCAM camera
NV-MX500 Mini DV camera
CVR 300AP Betacam camera
GY –DV 500E Mini DV camera
Quantity
2
4
3
3
3.4 Research Instruments
The following research instruments were used:
3.4.1
Job Cards:
Job cards that were used contained historical data. There were used in the UTV maintenance
workshop to store the following equipment repair data:
-
The job card number, date and time of reporting the fault. This was assumed to be the
date of occurrence of the fault.
56
-
The place of deployment and equipment details, that is, the type, model number and
serial number.
-
The fault description normally entered by the officer reporting the fault.
-
Equipment repairer findings and details of spares replaced.
-
Date of repair.
3.4.2
Questionnaire:
The questionnaire was designed as shown in the appendix and was used in WBS TV. It was used to
collect the following data:
-
Spares replaced over a period of one year for each machine and the cost of these spares.
-
The frequency of failure for each piece of equipment that is used to calculate the time
between failures.
-
Common faults for each category of equipment.
-
Type and frequency of preventive maintenance action.
-
Maintenance staff wages.
3.4.3
Spares Parts lists:
Spares lists were obtained in form of invoices and receipts and contained details of costs for spare
parts bought or ordered.
3.4.4
Interviews:
Interviews were carried out to supplement data that was obtained from job cards. This included:
-
Equipment hours of use per day.
-
Type and frequency of preventive maintenance action
57
3.5
Methods of Data Gathering in UTV
The following data was collected from workshop job cards from each specific machine mentioned
above:
(i)
Type, model number and serial number of machine.
(ii)
Job card Number.
(iii)
Date of occurrence of fault.
(iv)
Date of repair
(v)
Description of spares used
The time between failures in days (one day equal to 24 hours) was calculated using the calendar
function in Excel, Microsoft office 2007.
The cost of spares was obtained from invoices, from equipment manufacturers and their agents.
3.6
Methods of Data Gathering in WBS TV
The management and staff of WBS Television led by Mr. Elvis Sekyanzi (Managing Director) and
Mr Kazooba (General Manager) were pleased with the subject of the research. They said they
would strictly review the quantity, type and quality of data collected to ensure that sensitive
information would not land in the hands of their competitors. After interviewing the technical staff,
namely Mr. Nankunda , Mr Patrick Sembajjo and Mr. Ahmed Senabulya, The researcher concluded
that the methods used to assess equipment in UTV would not be applicable in WBS as there were
no formal workshop documents , for example, job cards. A decision was therefore made to use
methods of obtaining secondary data namely interviews and a questionnaire, which was reviewed
by the General Manager before it was handed over to the technical staff for filling. The objective of
the questionnaire was to obtain data on failure rates, common faults, common spares replacements,
58
type
and frequency of preventive action for the respective categories, taken during the period
covered by the study. It was found necessary to rely on staff‟s recollection due to lack of proper
records in this regard. The questionnaire was handed out to technical staff involved in the operation
and maintenance of equipment. It addressed the following:
9.
Manufacturer, model number and quantity of equipment used.
10.
Number of breakdowns reported.
11.
Common faults.
12.
Spares used and cost of spares.
13.
Type of preventive maintenance applied.
14.
Maintenance staff costs.
The questionnaire is shown in annex 2.
3.7
Purpose of Collecting Data from Workshop Job cards and Questionnaires
Failure data from workshop job cards and questionnaires was used as follows:
(i)
Calculation of time between consecutive failures (TBF) and subsequent calculation of
Mean Time Between failures (MTBF).
(ii)
Calculation of average quantity and type of spares per year per machine.
(iii)
Calculation of average maintenance staff wages.
(iv)
Identifying the most commonly failing components and their frequency of failure.
(v)
Calculating the percentage of the most expensive group of defects to the total spares cost
by method of Pareto Analysis.
(vi)
Testing the hypotheses
(vii)
Studying equipment operating conditions in direct relation to reliability.
59
3.8
Collection of Data from Equipment Catalogues and Manuals
Equipment catalogues were sought from equipment manufacturers and from the Internet.
The aim was to find out the following:
(i)
Preventive maintenance schedules as recommended by the equipment manufacturer.
(ii)
Manufacturer‟s acceptable MTBF.
(iii)
Cost of different types of spare parts.
The information so obtained was analysed as follows:
(i)
Comparison of the manufacturers MTBF with MTBF obtained from the research.
(ii)
Calculation of total cost of spares used.
3.9
Collection of data from available documents and interviews
A number of documents were consulted and several interviews carried out with staff and
management of the TV stations.
The aim was to find out the following:
(i)
Accuracy of maintenance data as obtained from Job cards and Maintenance log books.
(ii)
The scope of research in relation to other maintenance challenges in the respective
establishments.
(iii)
Maintenance strategies employed.
(iv)
Maintenance work flow.
(v)
Quality and size of maintenance staff
The information collected was analysed as follows:
(i)
Comparison of maintenance models between WBS and UTV.
(ii)
Putting other costs of failures other than costs of spares into perspective.
(iii)
The effect of quality and size of maintenance staff on equipment reliability.
60
CHAPTER FOUR
PRESENTATION AND INTERPRETATION OF RESULTS
4.1
Introduction
In this chapter the challenges of maintenance in UTV and WBS are presented. The maintenance
procedures in UTV and WBS are outlined culminating in diagrammatical interpretation of the UTV
and WBS maintenance work execution cycles. The maintenance strategies employed in UTV and
WBS are presented. Equipment failure costs are defined. The formats for tabulation of data in WBS
and UTV are explained. The Mean Time between Failures as a reliability parameter in the research
is mathematically defined. The cost of spares per machine per year as a maintenance cost parameter
is mathematically defined. Finally the data obtained from Job cards in UTV and Questionnaires in
WBS together with the calculated reliability and maintenance cost parameters are presented in a
tabular form.
4.2
Challenges of Maintenance in UTV
In order to provide TV services for 365 days a year, the following had to be maintained:

Ten transmitters spread all over the country. The transmitting sites comprised of
transmitter input equipment, modulating equipment and high power amplifiers, high
current three phase voltage regulators, satellite downlinks, transmission towers with
feeder cables and antennae bays, transmitter buildings, general power and lighting
equipment.

Satellite uplink equipment comprised of input equipment, digital to analogue converters,
modulating equipment, high power amplifiers, satellite dish and positioning system, high
current three-phase voltage regulator and uninterruptible power supply (UPS), satellite
shelter, general power and lighting equipment.
61

Studio equipment comprised of professional video tape recorders (VTR), video
processing, audio processing equipment, professional video cameras, video programme
monitors, vision mixers and sound mixers, audio and video monitoring equipment,
studio lighting equipment, satellite downlink and receiving equipment, three phase
voltage regulating equipment, general power and lighting equipment.

Outside broadcasting comprised of professional video tape recorders (VTR), video
monitors, vision mixers and sound mixers, audio and video monitoring equipment.

Postproduction, programme gathering and newsgathering equipment comprised of
professional videotape recorders, professional video cameras, video monitors, editing
equipment and accessories.
4.3
UTV Central Workshop
Most of the data collected in UTV was obtained from records of the central maintenance workshop.
Its activities are briefly described below.
The central workshop had the following objectives:

Providing a central location for the maintenance of equipment.

Reducing duplication of maintenance activities. This prevented different departments
from tying down their personnel to repair the same types of equipment .

Providing on the job training for technical staff.

Providing equipment redundancy. This was achieved by having a backup of repaired
equipment ready for deployment.

Carrying out acceptance testing, alignment and standardization.
62
4.4
Maintenance Documentation
Technical personnel in the different departments identified equipment that needed repair. A job card
was completed and sent to the central workshop together with the faulty piece of equipment. Items
entered on the job card by the reporting officer were:
-
Date of fault.
-
Equipment type, serial number and place of current deployment.
-
Fault description.
-
Name of officer describing the fault.
The job card was assigned a fault report number. The required spares were obtained from the stores
by completing a stores requisition form as shown below:
ITEM
UTV STORES WITHDRAWAL FORM:
DATE……….
To Ag.Supplies officer ,UTV stores.
Please issue the requested stores as noted below:DESCRIPTION
QUANTITY FOLIO/SERIAL NO
1
2
Requested by……………………………………………………….
Title…………………………………………………………………
Purpose……………………………………………………………..
Authorized by………………………Commissioner of Engineering
Or……………………………………………………………………
Fig.4.2 UTV stores requisition form
Title…………………………………..Date…………………………
Fig. 4.1.
UTV Stores withdrawal form
63
Specialization was not encouraged and all the technical staffs were expected to work on the
whole range of equipment. The figure below shows the job card that was issued by the
workshop.
Fault report No
Date
Time
Interruption of production
Place of deployment
Fault description
Name of describing officer
Examination results and mode/way of
removal of faults
Name
date
Spares requirements:
(a) Immediate
Source
Equipment type
(b) Future
File copy
Workshop engineers comments
Fig. 4.2.
UTV Engineering job card
On reception of equipment in the workshop, the fault number, equipment model number, serial
number and date of entry were entered into the workshop logbook. The job card was checked
for accuracy and repair work began. The results of examination and spares used were then
entered in the job card. After entering the engineer‟s comments, the job card was filed in the job
card file. The repaired machine was then returned to the user section.
64
The flow chart of maintenance work execution is shown below:
- Filing equipment
performance in studio log
book.
- Filing request for
equipment repair/servicing
in Studio log book.
-Receiving and installation
of repaired equipment.
Studio transmission shift
- evaluate request for
repair/service (carry out
first line maintenance).
Studio Engineer
Return
equipment to
studio
No
Does equipment
need repair?
Yes
- Issue job card
- Receive job card
- request/receive spare
parts from store
Workshop Engineer
No
Are spares available?
- Waiting file
- Go through
procurement process
- Store equipment
Yes
- Trouble shooting
- Spares replacement
- Equipment alignment
- Equipment servicing
Workshop technicians
Fig. 4.3. Flowchart of UTV maintenance work execution
65
4.5
Workshop Equipment Inventory
Inventory of equipment in the workshop was carried out on an annual or biannual basis. However
due to unavailability of spares a lot of equipment remained un-repaired in the workshop.
4.6
Maintenance Evaluation and Costing
Maintenance evaluation and costing was rarely done.
4.7
Maintenance Strategies and Forms
4.7.1 Failure based strategies (Breakdown maintenance):
These were employed on items of relatively little cost and which did not affect the essential
functioning of the system. These strategies were also used for equipment for which shutdown time
could have serious implications, for example, the final amplifier stage of the satellite uplink used to
distribute radio and TV programmes.
4.7.2 Condition based strategies:
These were employed on studio video tape recorders. Operation of the recorders was monitored on
a daily basis. Deviations from the normal operation were promptly reported. Action to be taken was
then determined.
4.8
Engineering Stores Management
4.8.1 Entering items in store
Purchases made were both local purchases and foreign purchases. Either method required the spares
purchased to be accompanied by a delivery note that contained the following information:
-
Date of delivery
-
File reference of local purchase order, invoice number or letter of credit number
-
Brief description of spares
-
Condition of spares
66
-
Name of supplier
-
Unique identifying marks and numbers on consignment
-
Details of transporters.
-
Name and title of receiving officer (by default the storekeeper)
The consignment was immediately given a stores reference number, for example, RV1/93/94
In case of foreign shipments, the delivery note would include details of the clearing agent. A
packing list would also be attached to the shipment.
The delivery note and the packing list were filed in a separate folder for future reference.
The stores system was based on ledger books with ledger forms.
At this point the following information was entered into the ledger
-
Details of supplier
-
Item number
-
Description of spare
-
Date
-
Stores reference number
-
Site
-
Quantity supplied
-
Total quantity available
-
Remarks about the particular spare
-
Bin number (This specified the exact location where the item was to be stored.
4.8.2 Storage locations
Most electronic spares are small and were stored in small plastic containers (bins). The places
where the bins were stored were called locations. One location contained several bins, for example,
location „A‟ could have bins 1 to 40.
67
4.8.3 Issuing of items from the store
Stores withdrawal forms were used for all issuing of items from the store and contained the
following information:
-
Date of request
-
Name and title of requesting officer.
-
Name and title of authorizing officer (normally head of department).
-
Description and quantity of spares.
-
Stores reference number.
A centralized form of maintenance was established in UTV in 1995.
The following information was found on the UTV workshop job cards:
1. Fault report number.
2. Date of report.
3. Description of equipment.(type, model and serial number)
4. Fault description.
5. Examination results and /or mode/way of removal of fault.
4.9
Challenges of Maintenance in WBS TV
In order to provide TV services for 365 days a year, the following had to be maintained:

Three UHF transmitters in Kampala, Jinja, Tororo and Mbarara. The transmitting sites
were comprised of transmitter input equipment, modulating equipment and high power
amplifiers, high current three phase voltage regulators, off air receivers, feeder cables
and antennae bays.

Studio equipment comprised of professional video tape recorders (VTR), video
68
monitors, vision mixers and sound mixers, audio and video monitoring equipment,
studio lighting equipment, satellite downlink and receiving equipment, three phase
voltage regulating equipment, general power and lighting equipment.

Outside broadcasting composed of video processing, audio processing equipment, video
cameras, video programme monitors, vision mixers and sound mixers, studio to
transmitter link, audio and video monitoring equipment.

Postproduction, programme gathering and newsgathering equipment composed of
professional videotape recorders, professional video cameras, editing equipment and
accessories.
All technical personnel were responsible for operation of studio equipment and maintenance of the
same.
Central maintenance workshop.
WBS run a small maintenance workshop within its premises. It is where faulty equipment was kept
and stored. This is also where records of each machine that were repaired are kept.
Maintenance methods
Both preventive and corrective maintenance methods were employed. Monday‟s Wednesdays and
Fridays were set-aside as maintenance days. Video cameras were cleaned and serviced on Mondays,
editing equipment ( VTRs, audio mixers, video mixers, computers, cabling and so forth.) were
serviced on Wednesdays , studio and master control room equipment were serviced on Fridays.
Non-scheduled maintenance was carried out on all days of the week. Fault reporting was made on a
daily basis through the chief technician to the engineer. Faults were prioritised according to the
consequences of equipment downtime.
69
Stores management
The need for spares was identified by the technical department and communicated to the general
manager. An order was then immediately placed with the supplier, for urgently required items, or
the Managing Director on one of his numerous foreign trips made a direct purchase. The technical
department also carried out direct purchase for locally available spare parts. All items procured
were entered into the data book. They were then immediately stored either in the central store or
technical store. It was also a common practice for spares to be installed immediately on arrival.
Spares were only removed from the store by filling out the stores requisition form. This was done
through the head of the technical department. Equipment inventory was carried out once a year.
The flowchart of WBS maintenance work execution is shown below:
70
- Filing equipment
performance in studio log
book.
- Filing request for
equipment repair/servicing
in Studio log book.
-Receiving and installation
of repaired equipment.
Studio transmission shift
- evaluate request for
repair/service (carry out
first line maintenance).
Chief technician
Return
equipment to
studio
No
Does equipment
need repair?
Yes
- request/receive spare
parts from store
Chief Technician
No
Are spares available?
- Notify General
Manager
- Store equipment
Yes
- Trouble shooting
- Spares replacement
- Equipment alignment
- Equipment servicing
Workshop technicians
Fig. 4.4 Flowchart of WBS maintenance work execution
71
4.10
Costs of Equipment failure
In both UTV and WBs the following were identified as costs of equipment failure
1.
Spares costs
2.
Loss of revenue caused by reduced capacity since less equipment is available when a
breakdown occurs.
3.
Staff wages and payments to staff for overtime or allowances to get the problem solved.
4.
Loss of revenue caused by start up and shutdown times as a result of poorly maintained
equipment as unfortunately happened in some instances.
4.11
Tabulation of Data Obtained in UTV
The following data was obtained from workshop job cards in UTV:
1.
Job card Number
2.
Date of reporting of the fault
3.
Date of repair.
4.
Description of spares used to achieve the repair
The following data was obtained from equipment catalogue and manuals:
1.
Cost of each spare part used
The following data was calculated:
1. Time between failures
2. Total cost of spares used per repair incident.
72
The above data was tabulated in the columns shown below:
DATA FOR …(equipment type)…………SERIAL NUMBER………….
Job card Date of fault Date of repair Time
A
B
between
failures
C
A1
B1
C1
A2
B2
C2
A3
B3
C3
An
Bn
Cn
Fig. 4.5
Spares used
D
Cost in
USD
E
D1
D2
D3
Dn
E1
E2
E3
En
Tabulation of data obtained in UTV
Annex 1 shows the tabulation of data obtained in UTV.
From the tabulation of equipment failure dates, repair dates and costs of repair, equipment
reliability and maintenance cost data was logically calculated by the author as follows;
4.11.1 Mean Time Between Failure as a Reliability Parameter
For constant failure rate, the observed mean time between failures, MTBF, was defined as:
 
T
(Equation 2.1), where T were the cumulative number of units of time when the machine
k
was in operation, under observation, (months, days, hours, minutes, seconds) and k were the
number of failures over period of observation T.
The Time To Repair (TTR) is defined as the date of repair minus the date of fault:
TTRn = B n  A n
……………………………………………………………………..4.1
The Time Between Failures (TBF) is defined as date of new fault minus date of repair of old fault:
TBFn = A n  B n  1 = Cn
……………………………………………………………..4.2
73
The Total machine operating days under the period of observation is defined as the sum of all the
times between failures:
k
T=
c
n
…………………………………………………………………………… 4.3
c2
Using the table above, it is very clear that the first result of the time between failures TBF can only
be calculated on the second failure occurrence and this therefore reduces the number of TBF values
to k – 1 since the value of C1 is undefined.
Assuming that the total downtime (TTR) was much less that the total uptime (TBF) we define
MTBF as:
k
C
MTBF =
n
……………………………………………………………………4.4
n2
k 1
where k are the number faults registered.
4.11.2 Cost of Spares per Machine per Year as a Maintenance Cost Parameter
The total cost of spares for the period of observation is defined as the sum of all the individual
spares costs during the period of observation:
k
E
=  E
OBSERVED
n
…………………………………………………………………….4.5
n 1
Cost of spares used per year for each particular machine was calculated after assuming that the total
downtime (TTR) was much less that the total uptime (TBF). Therefore cost spares used per year
became
k
E
365
E
YEAR
=
n 1
k
C
n
………………………………………………………………4.6
n
n 1
74
4.11.3 Frequency of Replacement of Identical Spare Parts as a Maintenance Cost
Parameter
The frequency of replacement, F, of identical spare parts is defined as the sum of times between
replacements divided by the number of times identical components were replaced, thus if  C i
Was the sum of times between replacements of component I and if the component was replaced j
times during the period of observation then
F =
i
 C ……………………………………………………………………………..4.7
i
j
The value of F is calculated for every component that is replaced more than once during the period
of observation.
4.12
Summary of Raw data from UTV
The tables below show values of T, K, E OBSERVED , MTBF, E YEAR and F for all equipment assessed
in UTV.
Table 4.1:
Equipment Model number
Equipment serial number
T (Total machine operating days
under period of observation )
K (Number of failures for period
of observation)
E OBSERVED (Total cost of spares
For period of observation)USD
MTBF (Mean time between
failures assuming constant failure
rate) days
E YEAR ( cost of spares per year
Data for video cameras in UTV
DXC3000AP
84765
606
DXC3000AP
84769
211
2
2
408.16
85.71
606
211
245.84
148.27
Assuming constant failure
rate)USD
75
Table 4.2:
Equipment
Model number
Equipment
serial number
T (Total
machine
operating days
under period of
observation )
K (Number of
failures for
period
of observation)
E OBSERVED (Total
Data for video tape recorders in UTV (Part 1)
BVU950 BVU950 BVU950 BVU950 BVU950 BVU950 VO9800P
13960
14055
14066
14076
14099
14127
18797
900
1714
1,041
1100
982
1169
1,136
6
10
13
11
5
10
6
723.14
1625.32
1,177.72
835.99
1126.6
1,562
487.69
190.44
86.75
110
245.5
129.9
227.2
346.12
412.94
277.40
418.75
487.8
156.70
609
1,041
387
-
927
776
cost of spares
For period of
observation)USD
180
MTBF (Mean
time between
failures
assuming
constant failure
rate) days
239.27
E YEAR ( cost of
spares per year
Assuming
constant failure
rate)USD
F
UPPER
_ DRUM
440
(frequency of
replacement of
upper
drum)days
F
BELT
_ LM
1105
900
-
242
-
-
(frequency of
replacement of
cassette loading
Motor belt) days
76
-
745
-
Table 4.3:
Equipment Model
number
Equipment serial
number
T (Total machine
operating days
under period of
observation )
K (Number of
failures for period
of observation)
E OBSERVED (Total cost
of spares
For period of
observation)USD
MTBF (Mean time
between failures
assuming constant
failure
rate)
E YEAR ( cost of spares
Data for video tape recorders in UTV (Part 2)
VO9800P
VO9850P
VO9850P
VO9850P
VO9850P
12747
12955
13651
13654
13655
479
535
1,341
202
2,260
7
8
11
5
5
340.93
948.76
1,135.82
54.59
86.35
79.83
76.43
134.1
50.5
565
259.8
647.28
309.15
98.64
13.95
479
-
-
75
per year
Assuming constant
failure rate) USD
F
REEL _ BELT
(frequency of
replacement of reel
belt) days
77
Table 4.4: Data for video monitors in UTV
Equipment Model
number
Equipment serial
number
T (Total machine
operating days
under period of
observation )
K (Number of
failures for period
of observation)
E OBSERVED (Total
cost of spares
For period of
observation)USD
MTBF (Mean time
between failures
assuming constant
failure
rate) days
E YEAR ( cost of
PVM1442QM
PVM1442QM
PVM1442QM
PVM1442QM
2005681
2005674
2005685
2006572
290
975
89
895
4
3
3
3
0
0
8.89
3
96.7
487.5
44.5
447.5
0
0
36.46
1.22
spares per year
Assuming constant
failure rate)USD
4.13
Tabulation of Data Obtained from WBS TV
Annex 2 shows the questionnaire that was sent to WBS TV.
Annex 3 shows answers to the questionnaire that was sent to WBS.
Data collected from WBS was tabulated in the columns shown below:
Equipment type……..
Equipment No
Number of
breakdowns
Years in service
1
2
3
n
Y1
Y2
Y3
Yn
Fig. 4.6
B1
B2
B3
Bn
Time between
Failures
(TBF)
TBF1
TBF2
TBF3
TBFn
Tabulation of data obtained from WBS TV.
78
From the tabulation of equipment years in service, number of breakdowns and costs of repair,
equipment reliability and maintenance cost data was logically calculated by the author as follows
4.13.1 Mean Time between Failure as a Reliability Parameter
(In the case of questionnaires)
From the figure above, Time Between Failures (TBF) is defined as:
365 x number of years equipment has been in service x hours it is in use per day.
Total number of failures during equipments service
TBFn (hours) =
365
Y
B
n
H
………………………………………………………………..4.8
n
where H represents the number of hours the equipment is in use per day.
The MTBF would therefore be defined as:
p
 TBF
MTBF =
n 1
n
……………………………………………………………………….4.9
p
where p is the number of pieces of equipment assessed.
Please note that for Bn = 0 in 4.8, the value of TBFn becomes undefined. In this case Bn is set to a
value of 1 (implying at least one failure) .Tables that include corrected values of Bn are shown in
the annex 6.
4.13.2 Cost of Spares per Machine per Year as a Maintenance Cost Parameter.
(In the case of questionnaires)
The average cost of spares per unit per year was defined as:
Total cost of spares used by all similar units per year
Total number of units assessed
79
4.14
Summary of Raw data from WBS TV
Table 4.5:
Equipment Model
number
Equipment
number
T (Total machine
operating days
under period of
observation )
K (Number of
failures for period
of observation)
MTBF (Mean
time between
failures assuming
constant failure
rate)
BVW75
PVW2800
PVW2800
PVW2800
PVW2800
PVW2800
1
1
2
3
4
5
1825
1460
1460
1278
1278
1278
11
10
13
6
4
5
2654.55
2336.00
1796.92
3406.67
5110.00
4088.00
Table 4.6:
Equipment
Model number
Equipment
number
T (Total machine
operating days
under period of
observation )
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures assuming
constant failure
rate)
Data for video tape recorders in WBS TV
Data for video tape recorders in WBS TV (Part 2)
DV/
VHS
DV/
VHS
DV/
VHS
DV/
VHS
DV/
VHS
DV/
VHS
D750
D750
1
2
3
4
5
6
1
2
1095
1095
1095
1095
1095
1095
365
548
3
4
2
6
1
5
1
1
5840
4380
8760
2920
17520
3504
5840
8760
80
Table 4.6:
Data for video tape recorders in WBS TV (Part 3)
UVW1800 UVW1800 UVW1800 UVW1800 UVW1800 UVW1800
Equipment
Model number
1
2
3
4
5
6
Equipment
number
730
730
547
1095
1095
730
T (Total
machine
operating days
under period of
observation )
3
2
2
6
5
3
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
3893.33
5840
4380
2920
3504
3893.33
rate)
Table 4.7:
Data for video monitors in WBS TV (Part 1)
PVM91CE PVM91CE PVM91CE PVM91CE PVM91CE PVM91CE
Equipment
Model number
1
2
3
4
5
6
Equipment
number
2281
2281
1887
1887
2190
2190
T (Total
machine
operating days
under period of
observation )
2
7
3
8
6
3
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
27375
7821.43
15096.4
5661.15
8760
17520
rate)
81
Table 4.8:
PVM91CE PVM91CE PVM91CE PVM91CE PVM91CE PVM91CE
Equipment
Model number
7
8
9
10
11
12
Equipment
number
2190
1551
1157
2190
2190
1825
T (Total
machine
operating days
under period of
observation )
3
4
8
6
0
3
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
17520
9307.5
3471.15
8760
0
14600
rate)
Table 4.9:
TM150
TM150
TVM9B
TVM9B
TVM9B
TVM9B
Equipment
Model number
1
2
1
2
3
4
Equipment
number
1460
1825
1704
1704
1704
1704
T (Total
machine
operating days
under period of
observation )
2
4
6
5
7
4
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
17520
10950
6818.2
8181.84
5844.17
10227.3
rate)
82
Table 4.10:
DU620
DU620
DU620
DU620
DU620
DU620
Equipment
Model number
1
2
3
4
5
6
Equipment
number
1825
1825
1825
1460
1095
2190
T (Total
machine
operating days
under period of
observation )
0
0
2
1
2
2
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
0
0
21900
35040
13140
26280
rate)
Table 4.11:
DU620
DU620
DU620
DU620
LHD6200 LHD6200
Equipment
Model number
7
8
9
10
1
Equipment
number
2190
2190
2190
2190
1095
T (Total
machine
operating days
under period of
observation )
2
1
2
0
2
K (Number of
failures for
period
of observation)
MTBF (Mean
time between
failures
assuming
constant failure
26280
52560
26280
0
13140
rate)
83
CHAPTER FIVE:
DISCUSSION OF RESULTS
5.1
Introduction
In this chapter the UTV and WBS maintenance models are discussed. The MTBF and cost of spares
per machine per year for each of the two stations is calculated proving that in both UTV and WBS
video tape recorders are the least reliable and most expensive to maintain whereas video monitors
are the most reliable and cheapest to maintain. The equipment hours of use per day for video
cameras, video cassette recorders and video monitors in UTV are calculated as a way of converting
the values of MTBF obtained from units of „days‟ to units of „hours‟. This is to enable the
standardisation of units of MTBF between UTV and WBS. Pareto analysis is carried out for failure
rates versus spares costs for video cassette recorders to prove that in the case of UTV 19% of the
total number of defects contributed 59% of the total spares cost. These were mainly video heads .In
WBS 46% of the total number of defects contributed 59% of the total spares cost. These were
mainly mechanical assemblies and sub assemblies. The cost of spares is plotted against the
frequency of maintenance to determine one cost saving strategy. The hypothesis is tested to with the
result that the alternative hypothesis is therefore upheld i.e. „broadcast equipment used by TV
stations in Uganda are not maintained to the reliability standards of the equipment manufacturers.‟
Finally research questions on the reliability for each category of equipment in Uganda, equipment
purchase criteria, reduction of maintenance costs and ways of increasing broadcast equipment
reliability are discussed.
5.2
Comparison of the UTV and WBS TV Maintenance Models
A study of the UTV and WBS TV maintenance models brought out the following salient features:
84
♦
UTV had a big maintenance workshop where a large number of faulty equipment was
stored. WBS had a small workshop with limited storage for faulty equipment.
♦
WBS run an elaborate schedule for cleaning of equipment. UTV never had such a schedule
and studio equipment was only occasionally cleaned on Fridays.
♦
The operating temperature of equipment in WBS was kept low by use of air-conditioning
equipment. Regulation of equipment temperature in UTV was erratic as the air conditioners,
where available, were mostly out of order.
♦
A deliberate effort was made in WBS to keep dust out of equipment areas by providing dust
proof seals for doors and by using air filters for ventilation ducts. The only method used in
UTV was regular mopping of the floor with a wet cloth.
♦
UTV employed job cards for recording equipment maintenance data. WBS employed log
books where limited details about equipment maintenance were stored.
♦
WBS employed direct procurement methods for purchase of spares .This method eliminated
procurement related delays thus reducing equipment downtime. They however stocked only
a few spare parts. UTV on the other hand employed a bureaucratic and lengthy procurement
system. Equipment downtime was kept low by stocking a large quantity of spare parts. The
relatively higher expenditure on spare parts by WBS could be attributed to the fact that the
programme production volume was higher than that of UTV thereby exerting greater wear
and tear on the equipment.
♦
In UTV there was a clear distinction between equipment operators and maintenance
personnel. In contrast all WBS technical personnel were responsible for the operation and
maintenance of studio equipment. UTV had a higher quality of maintenance personnel.
However this did not result in an increase in equipment reliability. In fact equipment in
WBS had higher reliability (see section 5.6).
85
The above comparison between the UTV and WBS maintenance models is summarised in the table
below.
Table 5.1
Summary of the UTV and WBS maintenance models
Factor
Workshop size
Adherence to equipment
cleaning schedule
Operating temperature of
equipment
Dust proofing of equipment
rooms
Methods of recording
maintenance and failure
data
Procurement of spare parts
Quantity of spare parts in
stock
Degree of specialisation of
maintenance staff
5.3
UTV
WBS
Large
Irregular
Small
Regular
High
Low (air conditioned)
Yes
No
Job cards
Log books
Log books
Slow (bureaucratic)
High (costly)
Fast (direct procurement)
Low
High
low
Calculation of MTBF and Cost of spares per machine
5.3.1 Statistical Treatment of Data Obtained from UTV
Statistical analysis was carried out on the following data obtained from UTV:
The statistical software package used was SPSS Ver.10.0 for windows.
The following were to be calculated for video tape recorders and video monitors ,using the data
collected:

Mean time between failure (MTBF)

Cost of spares per video tape recorder per year
The data collected was analysed using the descriptive analysis tool of SPSS Ver. 10.0 for
windows.
86
Video tape recorders
Values of time between failures (TBF) for 12 video tape recorders were extracted for every failure
occurrence and are shown below:
Table 5.2
210
66
150
84
182
243
33
28
75
Time between failures (TBF) for 12 video tape recorders for every failure occurrence
73
16
62
98
12
84
78
89
2
157
132
129
237
35
300
76
507
231
230
1105
266
30
63
392
37
34
1990
230
21
133
337
6
139
74
21
37
109
30
44
53
27
103
134
20
86
21
56
340
255
167
103
141
54
3
18
97
347
27
119
32
62
40
90
266
242
14
195
41
84
142
97
279
117
29
187
54
The results after statistical analysis are shown below:
Table 5.3
Results of descriptive analysis for values of Time Between failures (TBF) for video
tape recorders
Number of
samples N
85
Minimum
Maximum
2
1990
Mean
(MTBF)
151.28
Standard
deviation
250.42
Median
86
Cost of spares used per VTR per year for 12 video tape recorders were extracted for each video tape
recorder and are shown below:
Table 5.4
293.27
156.70
346.12
259.80
Spares used per video tape recorder per year (USD)
412.94
647.28
277.40
309.15
87
418.75
98.64
487.80
13.95
Table 5.5
Results of descriptive analysis for cost of spares used per video tape recorder per
year
N
Minimum
Maximum
12
13.95
647.28
Mean
(USD)
310.15
Standard
deviation
172.88
Median
301.21
Video Monitors
Values of time between failures (TBF) for 4 video monitors were extracted for every failure
occurrence and are shown below:
Table 5.6
1
Time between failures (TBF) for 4 video monitors for every failure occurrence
(days)
147
142
7
968
5
84
857
38
Table 5.7
Results of descriptive analysis for video monitors:
N
Minimum
Maximum
9
1
968
Mean
(MTBF)
249.89
Standard
deviation
380.76
Median
84
Cost of spares used per video monitor per year for four video monitors were extracted for each
video monitor and are shown below:
Table 5.8
0
Cost of spares used per monitor per year (USD)
0
36.46
1.22
Table 5.9
N
4
Descriptive analysis(spares used per monitor per year)
Minimum
0
Maximum
36.46
Mean
9.42
88
Standard deviation
18.04
5.3.2 Calculation of Equipment Hours of Use per Day in UTV
Manufacturers quote component replacement time in form of hours. It was therefore necessary to
convert the MTBF values obtained into hours .Six technical operators in UTV were interviewed to
find out the equipment usage in form of hours per day with the following results:
Table 5.10
Calculation of equipment hours of use per day in UTV.
EQUIPMENT operator operator operator operator operator operator
TYPE
1
2
3
4
5
6
MONITORS
16
13
14
8
13
10
VIDEOTAPE
RECORDERS
8
13
12
12
7
9
CAMERAS
10
4
14
6
9
5
Hours
per day
MEAN
12
10
8
The conversion rates for MTBF (days to hours) thus derived were therefore;10 hours per day for
video tape recorders, 12 hours per day for video monitors and 8 hours per day for video cameras.
These conversion rates are used in the summary of results from UTV below.
Table 5.11
MTBF (days)
Summary of results from UTV
MTBF (hours)
Cost of spares per
machine per year (USD)
151.28
1,512.8
310.15
249.89
2,998.7
9.42
Video monitors
408.5
3,268
165.78
Video cameras
From the three categories of equipment above it can be seen that video tape recorders are the least
reliable and most expensive to maintain. Video monitors are the most reliable and cheapest to
maintain.
5.3.3 Statistical Treatment of Data Obtained from WBS TV
Statistical analysis was carried out on the following data obtained from WBS TV:
The statistical software package used was SPSS Ver.10.0 for windows.
The following were to be calculated using the data collected:
89

Values of time between failures (TBF) for video tape recorders were extracted and are shown
below:
Table 5.12
TBF values for video tape recorders in WBS (hours)
2654.55
5110.00
5840.00
17520.00
4380.00
2336.00
4088.00
4380.00
3504.00
2920.00
1796.92
5840
8760.00
3893.33
3504.00
3406.67
8760
2920.00
5840.00
3893.33
Table 5.13
N
20
Minimum
2336.00
Results of descriptive analysis for video tape recorders:
Maximum
17,520.00
Mean
5067.34
Standard deviation
3476.53
Video Monitors

Values of time between failures (TBF) for video monitors were extracted and are shown below:
17520
8760.00
52560.00
43800
26280
Table 5.14
10950
17520.00
14600.00
43800
52560
TBF values for video monitors in WBS(hours)
27375.00
7821.43
15096.40
17520.00
9307.50
3471.15
6818.2
8181.84
5844.17
21900
35040
13140
26280
52560
13140
5661.15
8760.00
10227.3
26280
The above data was analysed using the descriptive analysis tool of SPSS Ver. 10.0 for windows.
The results are shown below:
90
Table 5.15
N
29
Minimum
3471.15
Results of descriptive analysis for video monitors:
Maximum
52,560.00
Mean
20,785.32
Standard deviation
15,293.67
Video Cameras

Mean time between failure (MTBF
Values of time between failures (TBF) for video cameras were extracted and are shown below:
Table 5.16
TBF values for video cameras (hours)
4380.00
8760.00
11694.60
4380.00
26280.00
3898.20
2920.00
13140.00
8760.00
13140.00
8760.00
3898.20
The above data was analysed using the descriptive analysis tool of SPSS Ver. 10.0 for windows.
The results are shown below:
Table 5.17
N
12
Minimum
2920.00
Results of descriptive analysis for cameras:
Maximum
26280.00
Mean
9167.58
Standard deviation
6548.33
The cost of spares for video tape recorderswas calculated from the questionnaire and tabulated as
shown below:
Table 5.18
Manufacturer
Sony
Sony
Panasonic
JVC
SONY
Cost of spares per year for video tape recorders in WBS (USD)
Model No.
Quantity
Total cost of spares per
year(USD)
BVW 75P
1
1100.00
PVW 2800P
5
8111.11
DVC-PRO AJ-D750 1
1200.00
DV/VHS
6
2075.01
UVW 1800P
6
8500.00
91
From the above table, the average cost of spares per video tape recorder per year was defined as:
Total cost of spares used up by all video tape recorders for one year
Total number of video tape recorders assessed
= 1104.53 USD per VTR per year
The cost of spares for video monitors was calculated from the questionnaire and tabulated as shown
below:
Table 5.19
Cost of spares for video monitors in WBS
Manufacturer
Model No.
Quantity
JVC
TM –150
PSNK
PVM 91CE
TVM9B 9
inches
DU 6 –20C
LHD 6200
2
Total cost of spares per year
(USD)
30.01
12
4
25.68
20.11
10
1
43.68
1.61
Sony
Vista
Melford
Philips
From the above table, the average cost of spares per video monitor per year was defined as:
Total cost of spares used up by all video monitors for one year
Total number of video monitors assessed
= 4.18 USD per monitor per year.
The cost of spares for video cameras was calculated from the questionnaire and tabulated as shown
below:
Table 5.20
Cost of spares for video cameras in WBS
Manufacturer
Model No.
Quantity
Sony
Panasonic
Sony
JVC
DSR – PD150P
NV-MX500
CVR 300AP
GY –DV 500E
2
4
3
3
92
Total cost of
spares per year
(USD)
1000.00
700.00
1680.00
680.00
From the above table, the average cost of spares per video camera per year was defined as:
Total cost of spares used up by all video cameras for one year
Total number of video cameras assessed
= 338.33 USD per video camera per year.
Table 5.21
Summary of results from WBS
Equipment
MTBF (hours)
Video cameras
Video monitors
5,334.04
9,167.58
20,785.32
Cost of spares per machine
per year
(USD)
1,104.53
338.33
4.18
From the three categories of equipment above it can be seen that in the case of WBS TV, video tape
recorders are the least reliable and most expensive to maintain. Video monitors are the most reliable
and cheapest to maintain.
5.4
Comparison of wages for maintenance staff between UTV and WBS
Studies carried out in UTV and WBS proved that labour costs in the form of wages for maintenance
staff substantially added to the cost of maintaining these pieces of equipment. Average wages for
maintenance staff at UTV stood at SHS 220,443/=. In comparison, average wages for maintenance
staff at WBS TV stood at SHS 511,111/=.
We can therefore say that on average WBS paid higher wages to maintenance staff than UTV.
5.5
Graphical representation of MTBF and maintenance costs in UTV and WBS
The above analysis is shown graphically below:
93
Cost of spares per year
per machine (USD)
1,200
1,000
800
600
400
200
0
UTV
WBS
Cameras
VTRs
Monitors
Fig 5.1 Cost of spares per machine per year (UTV&WBS)
20,785.32
20,000
UTV
15,000
10,000
5,000
9,167.58
3,268
WBS
5,334.04
1,512.80
2,998.70
0
Cameras
VTRs
Monitors
Fig 5.2 Equipment MTBF (UTV&WBS)
Average monthly
salary(Ushs)
MTBF(Hours)
25,000
600,000
511,111
500,000
400,000
300,000
220,443
200,000
100,000
0
UTV
WBS
Fig 5.3 Average wages for maintenance staff
94
Figures 5.3.7.1 and 5.3.7.2 show that WBS has generally higher equipment reliability than UTV but
also spends more on spares. Other factors that contribute to higher equipment reliability in WBS are
the following:

Presence of very stable power in WBS due to the use of an AC no break‟ power supply
i.e. the commercial mains input and standby generator power are channelled through a
UPS to the studio.

A relatively dust free environment in WBS.

Adherence to a strict preventive maintenance schedule mainly involving cleaning of
insides of equipment.

5.6
Higher remuneration leading to higher staff motivation (Fig.5.2.7.3).
Pareto Analysis
Pareto analysis was carried out on failure costs of video tape recorders in UTV and WBS to find
out the following:

The most expensive group of defects.

The most frequent defects.

The percentage cost of the most expensive group of defects to the total cost.
This was because video tape recorders were the most expensive to maintain. Video tape recorders
also had the widest variety of mechanical, electromechanical and electronic components thus
enabling clear categorization of defects. In UTV it was assumed that the cost of lubrication and
alignment per machine was 13.5 USD.
95
Results were tabulated as shown below:
Table 5.22
Pareto analysis of video tape recorders in UTV
Defect type
Mechanical adjustment and
lubrication
Mechanical assembly/subassembly
Electromechanical component
Electronic component
Electromagnetic pickup device
Frequency of
faults
33
Total cost (USD)
445.5
Percentage of total
cost
4.38
30
20
6
21
834.42
2437.6
730.81
5718.5
8.21
23.98
7.18
56.25
Electromechanical components were defined as devices that convert electrical signals into related
mechanical movement. These included electric motors and solenoids. Electromagnetic pickup
devices were defined as devices that pickup signals from magnetic tape using the electromagnetic
induction principle. These included video heads, audio heads, CTL heads and erase heads.
Table 5.23
Pareto analysis of video tape recorders in WBS TV
Defect type
Mechanical
assembly/subassembly
Electromechanical component
Electronic component
Electromagnetic pickup device
Frequency
Total cost
15
12,046
Percentage of
total cost
59
3
3
11
2,930
511
4,939
14.4
2.5
24.1
In the case of UTV it can be seen that 19% of the total number of defects contributed 59% of the
total spares cost. These were mainly video heads .In WBS 46% of the total number of defects
contributed 59% of the total spares cost. These were mainly mechanical assemblies and sub
assemblies. The wide disparity between UTV and WBS figures can be attributed to the fact that the
analysis for WBS was done over a shorter time span (one year).
The above results are shown diagrammatically below:
96
5.6.1 Graphical Representation of Results of Pareto Analysis
Electromagneti
c pickup fault
19%
Adjustment/lubr
ication
31%
Electronic fault
5%
Electromechani
cal fault
18%
Mechanical
fault
27%
Fig 5.4 Number of defects for video tape recorders in UTV
Adjustment/lub
rication
4%
Mechanical
8%
Electromechan
ical
24%
Electromagneti
c pickup
57%
Electronic
7%
Fig 5.5 Cost of spares for video tape recorders in UTV
97
Electromagneti
c pickup fault
34%
Mechanical
fault
48%
Electronic fault
9%
Electromechani
cal fault
9%
Fig. 5.6 Number of defects for video tape recorders in WBS
Electromagneti
c pickup fault
24%
Electronic fault
3%
Mechanical
fault
59%
Electromechani
cal fault
14%
Fig 5.7 Cost of spares for video tape recorders in WBS
98
5.7
The cost of spares versus frequency of maintenance
We shall define the frequency of maintenance as equal to
1
MTBF
Using data obtained above, composite graphs are drawn for cost of spares per year versus frequency
of maintenance for video tape recorders, video monitors and video cameras and are shown below:
1200
Cost of spares (USD)
1000
800
600
400
200
0
0
1
2
3
4
5
6
Frequency of maintenance per VTR (repairs per year)
Fig. 5.8
Cost of spares Versus frequency of maintenance for Video tape recorders
99
400
350
300
250
200
150
100
50
0
0
0.5
1
1.5
2
2.5
3
Frequency of maintenance per video camera (repairs per year)
Fig. 5.9
Cost of spares Versus frequency of maintenance for cameras
10
9
8
7
6
5
4
3
2
1
0
0
0.5
1
1.5
2
2.5
3
3.5
Frequency of maintenance per video monitor (repairs per year)
Fig.5.10
Cost of spares Versus frequency of maintenance for video monitors
From the graphs above we can generally conclude that in the case of video tape recorders and video
cameras , the cost of spares decreases with increased frequency of maintenance whereas in the case
of video monitors the cost of spares increased with increased frequency of maintenance.
100
5.8
Testing of hypothesis
5.8.1 Alternative hypothesis
Broadcast equipment used by TV stations in Uganda are not maintained to the reliability standards
of the equipment manufacturers
5.8.2 Null hypothesis
Broadcast equipment used by TV stations in Uganda are maintained to the reliability standards of
the equipment manufacturers.
It was required that the null and alternative hypothesis be tested against the separate categories of
equipment, namely;

Video tape recorders in UTV.

Video monitors in UTV.

Video cameras in UTV

Video tape recorders in WBS.

Video monitors in WBS.

Video cameras in WBS
In all the cases, the null hypothesis was defined as H
0

 where  is the value of MTBF
0
0
specified by the manufacturers. The alternative hypothesis was therefore defined as H
1

 . It
0
was assumed that data collected followed a normal distribution. This was done for a 95%
confidence interval, implying that 
 0 . 05
.
5.8.3 Testing hypothesis for the case of video tape recorders in UTV
For this case, n = 85, s = 2504.2,
x
=1512.8,
 = 1000, t
0
1
= 1.998 with n-1 degrees of freedom.
2
In the above, n is the sample size, s is the sample standard deviation,
101
x
is the sample mean, t 1   is
2
the value from the t distribution that corresponds to the degrees of freedom and confidence interval
specified.
We compute a 95% CL (confidence limit) on 
=
+ t 1
2
x
s
n
= 1512 + 1.998 x 2504.2/
85
= 970.14 to 2055.46.
The MTBF value of 1000 hours confidently falls within this interval. The null hypothesis is
therefore upheld for videotape recorders in UTV.
5.8.4 Testing hypothesis for the case of video monitors in UTV
For this case, n = 9, s = 4569.12,
x
= 2998.68,
 = 10,000 , t
0
1
= 2.306 with n-1 degrees of
2
freedom.
We compute a 95% CL on
=
x
+ t 1
2

s
n
= 2998.68 + 2.306 x 4569.12/
9
= 0 to 6510.81.
The MTBF value of 10,000 hours confidently falls outside this interval and is higher than the upper
value of the confidence interval. The alternative hypothesis is therefore upheld for monitors in
UTV.
5.8.5 Testing hypothesis for the case of video cameras in UTV
For this case, n = 2, ,
 = 38,200 , t
0
1
= 12.706 with n-1 degrees of freedom.
2
102
The MTBF value of 38,200 is much higher than  . The alternative hypothesis is therefore upheld
0
for video cameras in UTV.
5.8.6 Testing hypothesis for the case of videotape recorders in WBS
For this case, n = 20, s = 3476.53,
x
= 5067.34,
 = 1000, t
0
1
= 2.093 with n-1 degrees of
2
freedom.
We compute a 95% CL on 
=
x
+ t 1
2
s
n
= 5067.34 + 2.093 x 3476.53/
20
= 3440.29 to 6694.39
The MTBF value of 1,000 hours confidently falls outside this interval and is lower than the lower
value of the confidence interval. The Null hypothesis is therefore upheld for video tape recorders in
WBS.
5.8.7 Testing hypothesis for the case of video monitors in WBS
For this case, n = 29, s = 15,293.67,
x
= 20,785.32,
 = 10,000 , t
0
n-1 degrees of freedom.
We compute a 95% CL on 
=
x
+ t 1
2
s
n
= 20,785.32 + 2.048 x 15,293.67/
29
= 14,969.08 to 26,601.56
103
1
= 2.048 with
2
The MTBF value of 10,000 hours confidently falls outside this interval and is lower than the lower
value of the confidence interval. The null hypothesis is therefore upheld for monitors in WBS.
5.8.8 Testing hypothesis for the case of video cameras in WBS
For this case, n = 12, s = 6548.33,
x
= 9,167.58,
 = 38,200 , t
0
1
= 2.201 with
2
n-1 degrees of freedom.
We compute a 95% CL on
=
x
+ t 1
2

s
n
= 9,167.58 + 2.201 x 6548.33/
12
= 5006.94 to 13,328.22.
The MTBF value of 38,200 hours confidently falls outside this interval and is higher than the higher
value of the confidence interval. The alternative hypothesis is therefore upheld for cameras in WBS.
For the null hypothesis to hold it must hold for all cases, which is not true above as it failed to hold
in three out of six cases. The alternative hypothesis is therefore upheld i.e. broadcast
equipment used by TV stations in Uganda are not maintained to the reliability standards of
the equipment manufacturers.
5.9
Research Questions Answered
5.9.1 Research question 1
What is the reliability for each category of equipment in Uganda and how does it compare with
reliability figures from equipment manufacturers?
The table below shows reliability figures obtained from UTV and WBS. As comparison reliability
figures obtained from equipment manufacturers are shown.
104
Table 5.24
Equipment category
Video cameras
Video monitors
Reliability figures from UTV and WBS
MTBF (UTV)
3,268
1,512.8
2,998.7
MTBF (WBS)
9,167.58
5,334.04
20,785.32
MTBF
(equipment
manufacturers)
38,200
1,000
10,000
The above reliability figures show the following:

Video cameras in WBS are more reliable than those in UTV, but are only 25% as reliable as
the manufacturers‟ models.

Video tape recorders in WBS are more reliable than in UTV. The UTV reliability figures
approach those of the manufacturer by as low as 50 %. The WBS reliability figures are
however 400% higher.

Video monitors in WBS are more reliable than in UTV. The UTV reliability figures are
lower than those of the manufacturer (30% of the value). The WBS reliability figures are
however twice as high.
Which equipment purchase criteria should be used to tackle the issue of intrinsic or inherent
reliability?
The table below shows the most commonly occurring faults as obtained from data collected from
UTV and WBS TV.
Table 5.25
NATURE OF FAULT
Wear out of video head tips
leading to degradation of
recorded or playback
picture or complete loss of
Most common faults for video tape recorders
CAUSE
Head to tape friction since
there is direct contact
between the head and the
tape. Matters are made
105
COMMENTS
Replacement hours in UTV
are about 7,000 hours on
average whereas in WBS
they range between 3,000
picture.
Failure of the tape transport
mechanism due to worn out
mechanical parts i.e. Plastic
gears, belts, metallic and
plastic rollers, washers and
spacers.
Table 5.26
worse by the presence of
foreign materials on the
head tips or tape surface i.e.
dust, moisture, metal
particles, oil and greasy
compounds.
Friction between plastic and
plastic or between plastic
and metal is made worse by
the presence of dust or
metallic particles at the
contact surfaces. In some
cases greasing makes
matters worse by attracting
dust particles.
Recommendations to use
only the manufacturer‟s
recommended lubricants are
never followed.
Most common faults for video monitors
NATURE OF FAULT
CAUSE
Dry solder joints leading to
open or high resistance
connection between
electrodes and circuit.
High current flowing
through electrodes and
solder causes contraction
and expansion of solder.
Solder loses its
characteristics after several
cycles and develops cracks.
Sparking between contacts
wears them out after several
power cycles.
Failure of AC power switch
hours to 6,000 hours.
Breakdown of electrolytic
capacitors caused by
leakage of electrolyte
especially in power supply
and deflection circuits
High temperatures
generated in video monitor
circuits coupled with
presence of high voltage
across capacitor electrodes.
Leakage of EHT (Extra
High Tension) voltage,
typically 25KV, leading to a
breakdown of the deflection
circuit.
Ionisation of air within the
monitor and presence of
foreign particles increase
the conductivity of the air
especially around deflection
circuit and EHT electrode.
106
COMMENTS
Regular resoldering of the
circuit can solve this
problem.
This effect can be reduced
by limiting the number of
times a monitor is switched
on and off, or activating the
switch without presence of
power.
This problem can be
reduced by over specifying
the voltage rating of a
capacitor e.g. instead of
100uf 350V, replace with
100uf 450V.
Regular cleaning of the
circuitry can reduce this
problem. Silicon grease
should also be applied
around the EHT electrode
on the picture tube.
Table 5.27
Most common faults for video cameras
NATURE OF FAULT
Camcorders face a lot of
mechanical problems due to
miniaturisation of
components. It is therefore
common for tapes to jam
inside the camera.
CAUSE
Poor handling and care for
the camcorder and tape
mainly cause this. In some
models however
manufacturing defects
causes it.
Problems with the optical
system (lens) leading to
jamming of the zoom, focus
and iris control
mechanisms.
This is caused by presence
of dust and grease in the
lens system. Dust on the
lenses may partially
obstruct the picture.
COMMENTS
Avoiding the presence of
dirt in the camera
mechanism can reduce this
problem. Subjecting the
camera to extreme
vibration, shock,
temperature and humidity
should be avoided
Avoiding the presence of
dirt in the optical
mechanism can reduce this
problem
Arising from the above, the following criteria are useful when purchasing broadcast equipment:
 Care should be taken to purchase recorders designed for broadcast purposes. These recorders
have been designed with robust mechanical systems and long lasting video and audio heads.
The older broadcast formats were analogue in nature i.e. Umatic SP, Betacam SP and so
forth. The new broadcast formats are digital in nature i.e. DVCAM, DVCpro , Digital
Betacam, HDV, DVDR and so forth. On the whole, digital formats deliver a more stable
high picture quality. They however have lower tolerances for dust and extreme temperature
variations. Domestic type recorders should be avoided, as these are not reliable. These
include the VHS, DV and Video 8 formats.
 There must be a guarantee from the supplier that the manufacturer will be able to supply
spare parts for the duration of estimated equipment life. It is only the steady supply of spare
parts that can make equipment reliable.
107
Video cameras
 As with video tape recorders, care should be taken to purchase recorders designed for
broadcast purposes. These recorders have been designed with robust mechanical systems
and long lasting video and audio heads.
 There are other characteristics to look out for that may impinge on reliability. The optical
zoom, where the focal length of the lens is changed, must be servomotor driven and not
synthesised through electronics to ease service of the lens system. The cassette loading
mechanism must be side mounted. The camera must be of 3 CCD chip design. The camera
must have professional output ports that are not easily damaged i.e. video outputs and inputs
must use BNC connectors and audio inputs and outputs must use XLR connectors.
 As with video tape recorders, there must be a guarantee from the supplier that the
manufacturer will be able to supply spare parts for the duration of estimated equipment life.
Video monitors
 Video monitors must be of robust design with sufficient ventilation slots on the covers to
permit free circulation of air.
 Video monitors must be of an open design that is easy to open and dust. This means that it
must have few, well spaced, circuit boards.
 As with video tape recorders, there must be a guarantee from the supplier that the
manufacturer will be able to supply spare parts for the duration of estimated equipment life.
How can maintenance costs be reduced without adversely affecting reliability?
Investigations were done and comparison was made between the manufacturers recommended
preventive spares replacement schedules and replacement schedules discovered in actual practice.
108
For the case of UTV there was sufficient data to analyse replacement schedules for the following
parts used in video tape recorders:
Table 5.28
TYPE
BVU950
BVU950
BVU950
BVU950
BVU950
BVU950
BVU950
V09850
VO9850
Number of days between successive replacements.
SERIAL No
UPPER DRUM BELT,LM
REEL BELT
13960
440
900
14055
609
14055
1105
14066
1041
14076
387
14127
927
745
14127
242
18797
776
12747
479
MEAN
690.9
822.5
479
Table 5.29
Recommended replacement hours and actual replacement hours in UTV
Manufacturers
Estimated replacement hours in
Item
recommended
UTV
replacement hours
Upper drum assembly
1,000
6,909
(video head) DUR44
Belt LM
4,000
8,225
3-653-387-00
Reel belt (belt square)
4,000
4,790
3-672-737-01
From the above, it can therefore be concluded that in the case of video tape recorders, it is possible
to reduce maintenance costs by using the components beyond their recommended hours of
replacement. This also increases the reliability of equipment since the MTBF will have effectively
gone up.
109
How can broadcast equipment reliability be increased?
It has been stated that „if the desired performance of an asset exceeds its built in capability, it is in a
failed state right from the outset and no amount of maintenance will deliver the desired
performance. This problem can only be solved by redesigning the asset to increase its built in
capability, or by lowering performance expectations to a level at which the asset can cope‟
(Moubray: Reliability centred maintenance, 1993).
Broadcast equipment are manufactured outside Africa and in the case of Uganda, the level of
technological development, in the context of tools and expertise necessary to redesign the
equipment, does not permit redesigning to take place. The only way forward therefore is to look at
factors that lead to low reliability of equipment and address them.
Research carried out in WBS TV and UTV came up with factors and recommendations as follows:
 There was presence of dust in equipment. In the case of video tape recorders, this was
responsible for the high wear and tear of moving parts. In the case of video monitors the
dust formed a thick layer on the components‟ surface leading to overheating of the
components and their eventual failure. In this case operating the equipment in a dust free
environment and increasing the frequency of dusting the equipment would increase
reliability.
 The equipment goes through a high number of power cycles due to load shedding.
The resultant electrical stress exceeds the stress margins of the electrical components
causing them to break down. In this case putting all the equipment on an uninterruptible
power supply (UPS) will lead to higher reliability. This has been done in WBS but has not
been done in UTV.
110
 In UTV there was very little money allocated for purchase of spare parts. In addition the
procurement process was very lengthy for spares purchased outside Uganda. This led to
lengthy downtimes. In this case, timely purchase of spare parts and use of prediction
methods will lead to higher reliability.
 Field cameras (camcorders) were subjected to excessive temperatures, vibration and shock.
This was especially true in WBS where hectic recording schedules were prevalent. Whereas
excessive temperature led to breakdown of electronic components, vibration and shock led
to misalignment of the mechanical parts. In this case proper cushioning by carrying
equipment in the manufacturer’s recommended carrying case/bag and use of heat
shielding equipment, for example, umbrellas will lead to higher reliability.
 There was use of very old equipment i.e. equipment outside its useful life cycle. The
maintenance cost associated with maintaining an acceptable equipment reliability level was
therefore too expensive and the cost and availability of spare parts had become unacceptable
from an economic standpoint. Failure to meet this cost therefore led to low reliability. This
was especially true of UTV and to a lesser extent WBS. In this case there should be a life
cycle reliability strategy developed and adhered to from equipment purchase
specification criteria to decommissioning. Equipment outside its useful life cycle should
be decommissioned and new equipment bought.
111
CHAPTER SIX:
SUMMARY AND RECOMMENDATIONS
6.1
Restatement of the Problem
The research focused on the hypothesis that equipment used in broadcasting stations in Uganda had
low reliability. There was therefore a need to assess reliability and look into factors affecting it in
order to increase the reliability of equipment, reduce maintenance costs and increase the lifetime of
equipment. The intended result was to increase the profitability of TV stations.
6.2
Description of Procedures
In UTV, the data collected that included equipment models, date of fault, date of repair and spares
used was obtained from workshop job cards. The cost of spares was obtained from spares purchase
documents and suppliers‟ sites on the Internet. It was therefore possible to calculate the TBF (time
between failures) and MTBF (mean time between failures) and cost of spares used per year.
Interviews were carried out to assess patterns of equipment use.
In WBS, the data collected that included equipment models, quantities, rate of breakdown, spares
used and cost of spares was obtained by way of questionnaire and interviews. It was therefore
possible to calculate the TBF, MTBF and cost of spares used per year.
Statistical analysis using the t distribution was used to assess the 95% confidence limits of TBF data
for the different categories of equipment. The null and alternative hypotheses were tested by
comparing the confidence limits with MTBF values obtained from equipment manufacturers.
Research questions were answered using data collected from WBS, UTV, and equipment
manufacturers‟ reliability data and from interviews with maintenance personnel. It was therefore
possible to fulfil the objectives of the research. This was the assessment of reliability for three
112
categories of broadcast equipment, researching the most commonly occurring faults and arriving at
the best maintenance strategy for each category of equipment.
6.3
Major Findings
The major findings of the study were:

In both UTV and WBS video tape recorders are the least reliable and most expensive to
maintain whereas video monitors are the most reliable and cheapest to maintain.

The cost of spares per year reduced with increased frequency of maintenance for video tape
recorders and video cameras resulting in a 30% reduction in cost for every 100% increase in
frequency of maintenance in the case of video cameras and in a 37% reduction in cost for
every 100% increase in frequency in the case of video tape recorders.

The cost of spares per year increased with increased frequency of maintenance for video
monitors resulting in a 42% increase in cost for every 100% increase in frequency of
maintenance.

The null hypothesis was rejected and the alternative hypothesis adopted i.e. broadcast studio
equipment used by TV stations in Uganda are not maintained to the reliability standards of
equipment manufacturers.

Broadcast equipment reliability in Uganda can be increased by including specifications in
procurement documents that favour the acquisition of reliable equipment.

Pareto analysis showed that mechanical parts, electromechanical parts and electromagnetic
pickup parts took up the lion‟s share of spares costs in video tape recorders (88.44% in case
of UTV and 97.5% in the case of WBS TV).

Maintenance records in some broadcasting stations were not properly kept.

The innovative approach of using a questionnaire to generate maintenance data proved to be
successful.
113
6.4
Contribution of the thesis to the field of engineering
Reliability Engineering consists of the systematic application of time-honoured engineering
principles and techniques throughout a product lifecycle. The goal of reliability engineering is to
evaluate the inherent reliability of a product or process and pinpoint potential areas for reliability
improvement. Realistically, all failures cannot be eliminated from a design, so another goal of
reliability engineering is to identify the most likely failures and then identify appropriate actions to
mitigate the effects of those failures.
In Uganda no reliability evaluation of broadcast equipment has taken place yet the most important
contribution of engineering to the broadcasting sector is to ensure that equipment correctly perform
their intended function in the most efficient and cost effective way possible.
The contribution of this research therefore was to assist engineers in the broadcast industry to adopt
engineering practices and put in place measures to ensure that expensive broadcast equipment
continuously perform their function in the most cost efficient and productive way.
The ingenious method of using questionnaires to assess reliability further adds to the relevancy of
the thesis to developing countries as it enables reliability assessment where little or no historical
failure data exists.
6.5
Recommendations
It is felt that the following recommendations arising out of the research should be adopted by TV
broadcasting stations in Uganda for purposes of improving equipment reliability:

Maintenance personnel in broadcasting stations should concentrate their efforts on
preventive maintenance of video tape recorders and video cameras since it results in savings
of spares costs.
114

Broadcast studio equipment reliability should be increased by including specifications in
procurement documents that favour the acquisition of reliable equipment.

Maintenance costs of video tape recorders can be reduced by operating them in a clean dust
free, cool environment and by regular cleaning and lubrication of mechanical parts. This will
reduce costs associated with replacement of mechanical parts and electromagnetic pickup
parts, these being the major contributors to spares costs.

Equipment that is used outside the manufacturer‟s stipulated lifetime attracts high
maintenance costs in terms of the quantity of spares needed and the increasing costs of
obtaining those spares. Such equipment should always be decommissioned. In the case of
UTV and WBS, some of the equipment had reached its useful life. Such equipment should
be decommissioned.

Maintenance personnel should always be technically alert and not just wait for equipment to
go down before attempting repair of the same. This attitude also points to a poor
maintenance culture in Uganda.
♦
The managers of television stations in Uganda need to establish reliability maintenance
processes in their firms. They should do so by setting up plant registers with a view to
enhance understanding of how equipment works, how it can fail and the root causes of each
failure. They should also ensure that maintenance personnel possess and implement
maintenance schedules. They should also involve maintenance staff and equipment
operators in the formulation of specifications for new equipment purchases.
6.6
Recommendations for Further Investigation
Research into equipment reliability in Uganda should be continued in the following areas:

Reliability of Transmitters. During the time of this study there was insufficient data on
transmitters. The study therefore focused on studio equipment. Transmitters in Uganda have
115
since grown in number. It may therefore be possible to carry out a reliability study on
transmitters.

The cost of equipment replacement as opposed to cost of repair. This is an area of contention
as some argue that it is cheaper to replace equipment than to maintain it.

Investigations should be made into change of reliability patterns with change in equipment
technology. This involves continuous collection of reliability data as more TV stations are
established and as the old ones acquire new equipment. New issues associated with adoption
of new technology will therefore have to be addressed, for example, software reliability.
116
BIBLIOGRAPHY
1. Nippon Hoso Kyokai Public Relations Department(2008/2009). NHK annual report 2008/2009
Website: http://www.nhk.or.jp/pr/english/annual/2008/pdf/whole.pdf (visited on 22/05/2010).
2.
Nippon Hoso Kyokai Public Relations Department(2009/2010). NHK annual report 2009/2010.
Website: http://www.nhk.or.jp/pr/english/annual/2008/pdf/whole.pdf (visited on 22/05/2010).
3. South African Broadcasting Corporation. (2006) . SABC annual report 2006.
Website: http://annualreport.sabc.co.za/annual06/pdf/sabcar06.pdf (visited 22/05/2010)
4. Africa Media Initiative (2006).Uganda Country report context Television BBC World Service
Trust. Website: http:// downloads.bbc.co.uk/ worldservice/trust/ pdf/AMDI/uganda/
amdi_uganda6_television.pdf (visited 22/05/2010)
5. Berwanger,Dietrich (1987) . Television in the third world. New technologies and social change.
Bonn; Friedrich-Ebert-Stiftung (FES).
6. Africa Media Initiative (2006).Kenya Country report context radio BBC World Service
Trust.Website: http:// downloads.bbc.co.uk/ worldservice/trust/pdf/ AMDI/ kenya/
amdi_kenya5_radio.pdf (visited 22/05/2010)
7. Hisham Bin Jabar(2003) (Plant maintenance strategy; key for enhancing profitability
Maintenance resources Inc.
Website:http://www.maintenanceresources.com/referencelibrary/ezine/chemclean.htm (visited
22/05/2010)
8. Lakshminarayanan, V. (2001). Failure analysis techniques for semiconductors and other
devices.
RF
design
edition
February
2001
pp
34-38
Website:http://mobiledevdesign.com/images/archive/0201Lakshim34.pdf Last Accessed 31st
May 2010.
9. Smith, J, David, (2001). Reliability, Maintainability and Risk. Practical methods for engineers
(6th ed.). Oxford; Butter worth Heinemann. pp 12-20.
10. Shepherd, J , Morton, A, H, & L, F, Spence (1978). Higher electrical engineering (2nd
ed.).London; Pitman Publishing Ltd. Pp 850-867.
11. Cluley,J,C (1981) . Electronic Equipment Reliability. London;The Macmillan Press LTD
12. Kawauchi, Yoshio & Marvin Rausand (1999). Life cycle cost (lcc) analysis in oil and chemical
process industries P.3. Website:http://www.ntnu.no/ross/reports/lcc.pdf . Last Accessed 31st
May 2010
117
13. Sony Corporation, (1989) . Professional Umatic SP videocassette recorder BVU 950P
maintenance manual (1st ed.) . (vol. 1) Japan: Author. p.3-10.
14. Smith , J , David , (1988). Reliability and maintainability in perspective .Practical
,Contractual, Commercial and software aspects(3rd ed.). London ; Macmillan education Ltd.
15. Wavah Broadcasting Services website (WBS-TV) Home Page
Website: http://www.wbs-tv.com Last accessed on 31st May 2010
16. United States department of labour, Bureau of labour (2009). statistics Career Guide to
Industries, 2010-11 Edition: Broadcasting
Website:http://www.bls.gov/oco/cg/cgs017.htm Last accessed 31st May 2010.
17. International atomic energy agency (2007). Implementation Strategies and Tools for Condition
Based Maintenance at Nuclear Power Plants
Website:http://www-pub.iaea.org/MTCD/publications/PDF/te_1551_web.pdf.Last
Accessed
31st May 2010
118
ANNEX 1: TABULATION OF DATA OBTAINED FROM UTV
JOB CARDS
A1.1 Tabulation of Data for Video Tape Recorders
The following pages show tabulated data for video tape recorders
A1.1
Data for video tape recorder Umatic SP BVU 950P serial no 13960
Job
card
070
127
Date of
fault
31/7/97
27/2/98
Date of
repair
1/8/1997
2/3/1998
Time between
failures
149
17/4/98
18/4/98
73
183
225
255
22/9/98
23/9/98
11/5/1999 19/5/99
4/1/2000 5/1/2000
A1.2
Spares used
upper drum
pinch roller
assy,beltLM
cleaning and
lubrication
upper drum
box block assy gear
belt LM
210
157
230
230
Cost in
USD
333.32
32.38
0
333.32
22.22
1.9
Data for video tape recorder Umatic SP BVU950P serial no 14055
Job card
Date of
fault
Date of
repair
Time
between
failures
065
24/7/97
25/7/97
104
123
150
166
11/11/1997
26/02/98
22/04/98
24/06/98
2/12/1998
27/02/98
23/04/98
25/06/98
109
86
54
62
182
17/9/98
18/9/98
84
197
23/11/98
24/11/98
66
204
220
10/12/1998
22/4/99
11/12/1998
23/4/99
16
132
028/2000
2/5/2002
2/5/2002
1105
119
Spares used
cost in USD
upper drum
assy
roller rings
gear box
belt LM
lubrication
and
adjustment
roller block
assy pinch
alignment
and
lubrication
alignment
upper drum
assy
upper drum
assy,lower
drum
333.32
5.7
22.22
1.9
0
30.48
0
0
333.32
898.38
A1.3
Job card Date of
fault
041
13/5/1997
052
4/6/1997
Date of
repair
14/5/1997
10/6/1997
Time between
failures
060
069
075
081
120
169
179
208
10/7/1997
31/7/97
4/8/1997
18/9/97
11/2/1998
13/7/98
14/9/98
22/01/98
10/7/1997
1/8/1997
9/8/1997
22/9/97
13/02/98
14/7/98
15/9/98
1/2/1998
30
21
3
40
142
150
62
129
248
257
262
25/10/98
7/3/2000
21/4/2000
26/10/98
17/4/2000
22/4/2000
266
133
44
A1.4
21
Spares used
Cost in USD
upper drum
pinch roller,threading
ring
adjustment
cleaning ,lubrication
roller rings
adjust cdsand rv302
Belt LM,brush assy
adjust tape top sensor
TU reel assy, head
erase
box block assy gear
head drum motor
333.32
126.98
0
0
5.7
0
0
62.22
0
62.22
22.22
0
565.06
Data for video tape recorder Umatic SP BVU 950P serial no 14076
Job card Date of
fault
050
9/5/1997
Date of
repair
29/5/1997
Time between
failures
064
077
100
122
160
181
24/7/1997
12/8/1997
11/11/1997
24/2/1998
20/5/1998
15/9/1998
25/7/1997
13/8/1997
19/11/1997
25/2/1998
9/6/1998
16/9/1998
56
18
90
97
84
98
223
231
263
268
11/5/1999
11/6/1999
16/5/2000
9/7/2000
12/5/1999
14/06/1999
17/5/2000
11/7/2000
237
30
337
53
120
Spares used
Cost in USD
cleaning and
lubrication
upper drum assy
toggle switch
realignment
realignment
audio CTL head
upper drum assy,belt
LM
roller block assy
Box block assy gear
alignment
alignment
0
333.32
6.35
0
0
85.71
335.22
53.17
22.22
0
0
A1.5
Job card Date of fault Date of repair Time
between
failures
053
30/05/97
12/6/1997
157
175
227
256
18/05/98
26/08/98
20/05/99
24/02/2000
A1.6
21/05/98
27/08/98
21/05/99
28/02/2000
340
97
266
279
Spares used
Cost in
USD
Belt LM,ring assy
main
pinch solenoid
table(T) assy reel
upper drum assy
head ACE,DUH
44BR
98.4
32.05
12.06
333.32
650.77
Data for video tape recorder Umatic SP BVU950P serial no14127
Job card Date of
fault
Date of
repair
Time
between
failures
080
138
18/9/97
23/3/98
22/9/97
25/3/98
182
144
153
170
171
173
6/4/1998
11/5/1998
13/7/98
20/7/98
17/8/98
6/4/1998
11/5/1998
14/7/98
21/7/98
17/8/98
12
35
63
6
27
222
29/4/99
29/4/99
255
261
10/4/2000 10/4/2000 347
013/2000 8/12/2000 8/12/2000 242
Spares used
Cost in USD
upper drum assy
belt square,belt
LM,power unit
alignment
upper drum assy
roller block assy
alignment
lubrication and
alignment
box block assy,ring
assy main
upper drum, belt LM
upper drum
333.32
55.23
121
0
333.32
53.17
0
0
118.72
335.22
333.32
A1.7
Data for video tape recorder Umatic SP VO9800P serial no 18797
Job card Date of
fault
241
24/08/99
Date of
repair
25/08/99
Time between
failures
252
20/12/99
22/12/99
117
005/2000
014/2000
023/2000
031/2000
21/08/2000
13/11/2000
10/9/01
8/10/02
21/08/2000
14/11/2000
11/9/01
8/10/02
243
84
300
392
A1.8
Spares used
capacitor 100uf
16V
Dial block
assembly, search
upper drum assy
belt,LM ,gear box
Alignment
upper drum assy
Cost in
USD
2
46.35
207.61
24.12
0
207.61
Job
card
068
132
Date of
fault
30/7/97
17/12/97
Date of
repair
31/7/97
17/12/97
Time between
failures
141
180
186
190
30/3/98
14/9/98
12/10/98
27/10/98
31/3/98
15/9/98
13/10/98
29/10/98
103
167
27
14
199
27/11/98
28/11/98
29
Spares used
reel belt
swich toggle ( AC
power)
AC-98 board
belt,LM
Audio /CTL head
upper drum assyand
pinch roller
reel belt
139
122
Cost in
USD
1.9
6.35
5.08
1.9
85.71
238.09
1.9
A1.9
Job
card
094
105
124
Date of
fault
5/11/97
8/12/97
26/2/98
Date of
repair
5/11/97
10/12/97
27/2/98
Time between
failures
156
14/5/98
18/5/98
76
165
176
24/6/98
7/9/98
25/6/98
9/9/98
37
74
209
21/01/99
4/2/99
134
226
18/05/99
18/05/99
103
Spares used
belt(67x2)/reel belt
belt(67x2)/reel belt
gear box and pinch
roller
capstan motor and
drum motor
lubrication/alignment
reel motor 8-835-40901
cassette up block
assembly
PS503(link IC) on SY141
33
78
Cost in
USD
1.9
1.9
52.7
728.86
0
53.97
107.93
1.5
A1.10 Data for video tape recorder Umatic SP VO9850P serial no 13651
Job card Date of
fault
048
9/5/97
084
25/9/97
Date of
repair
29/5/97
26/9/97
Time between
failures
146
187
196
213
9/4/98
13/10/98
11/11/98
17/2/99
9/4/98
14/10/98
20/11/98
18/2/99
195
187
28
89
001/2000
003/2000
006/2000
010/2000
018/2000
9/7/00
14/8/2000
4/9/00
25/9/2000
14/2/2001
11/7/00
14/8/2000
5/9/00
26/9/2000
14/2/2001
507
34
21
20
141
Spares used
threading ring
alignment,
resoldering
power socket
alignment
alignment
upper drum assy,
belt LM
alignment
alignment
alignment
alignment
MD 60 circuit
board
119
123
Cost in
USD
96.5
0
5
0
0
334.32
0
0
0
0
700
A1.11 Data for video tape recorder Umatic SP VO9850P serial no 13654
Job
card
058
Date of
fault
4/7/97
Date of
repair
7/7/97
Time between
failures
074
082
098
8/8/97
19/9/97
12/11/97
9/8/97
19/9/97
13/11/97
32
41
54
117
27/1/98
27/1/98
75
Spares used
dial block ass'y
search
alignment
alignment
Idler,belt Lm, reel
belt
reel belt
Cost in
USD
46.35
0
0
6.34
1.9
A1.12 Data for video tape recorder Umatic SP VO9850P serial no13655
Job card Date of
fault
076
22/7/97
079
14/8/97
143
3/4/98
036/2000 15/09/2003
039/2000 7/11/03
Date of
repair
12/8/97
15/8/97
4/4/98
1/10/03
13/11/2003
Time between
failures
2
231
1990
37
124
Spares
used
Pinch roller
alignmrnt
belt,LM
reel motor
realignment
Cost in
USD
30.48
0
1.9
53.97
0
A1.2 Tabulation of Data for Video Monitors
The following pages show tabulated data for video monitors
A1.13 Data for video monitor Sony PVM1442QM serial no 2005681
Job
card
040
044
088
125
Date of
fault
5/5/1997
7/5/1997
6/10/1997
26/2/98
Date of
repair
6/5/1997
12/5/1997
7/10/1997
28/2/98
Time between
failures
1
147
142
Spares
used
resoldering
resoldering
resoldering
resoldering
Cost in
USD
0
0
0
0
Job
card
190
043/97
254/97
Date of
fault
29/4/97
7/5/1997
3/1/2000
Date of
repair
30/4/97
10/5/1997
5/1/2000
Time between
failures
Spares used
resoldering
resoldering
Capacitor c547 160V
3.3 uf
7
968
Cost in
USD
0
0
5
Job
card
092
Date of
fault
27/10/97
Date of
repair
30/10/97
Time between
failures
097
198
4/11/1997 10/11/1997 5
2/2/1998 3/2/1998
84
Spares used
AC power
swich,resoldering
resoldering
resoldering
125
Cost in
USD
8.89
0
0
Job
card
067
250
Date of
fault
17/7/97
3/12/1999
Date of
repair
29/7/97
3/12/1999
Time between
failures
253
10/1/2000
10/1/2000
38
Spares used
resoldering
7812 12 volt
regulator
resoldering
857
Cost in
USD
0
3
0
A1.3 Tabulation of Data for Video Cameras
The following pages show tabulated data for video cameras
A1.17 Data for video camera DXC3000AP serial no 84765
Job card
Date of
fault
Date of
repair
168
12/7/98
12/7/98
258
9/3/00
11/3/00
Time
between
failures
606
Spares used
Cost in
USD
IE-14P
board
IC 8
TC4053BP
on EN 39A
403.16
5.00
A1.18 Data for video camera DXC3000AP serial no 84769
Job
card
095
158
Date of
fault
4/11/97
4/6/98
Date of
repair
5/11/97
4/6/98
Time between
failures
Spares used
Alignment,cleaning
viewfinder board
VF-23
211
126
Cost in
USD
0
85.71
ANNEX 2: QUESTIONNAIRE THAT WAS SENT TO WBS
CODE NO ………………..
TV STATION…………………….
I‟m a master of Engineering student from Makerere University. I‟m studying the reliability of
broadcast equipment. The aim of the study is to assess the reliability and maintenance costs of
various categories of broadcast equipment focusing on television stations in Uganda.
This questionnaire is to assess reliability of three categories of equipment; video cameras, video
monitors and video tape recorders. It will be based on your recollection of the behavior of these
types of equipment. You are encouraged to consult relevant documents where available and attach
copies to the questionnaire. Your contribution will help towards formulation of methods to
improve reliability and is much appreciated.
The information given is taken in strict confidence and is for purposes of research only.
SECTION A:
15.
Manufacturer
Please describe the type and quantity of video monitors in your station
Model No.
Quantity
……………………………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………………….
…………………………………………………………………………………………
………………………………………………………………………………………….
2. How many hours are these monitors switched on per day? (one day = 24hours)
…………………………………………………………………………………………
3. How many times has each monitor broken down in the past year?
Monitor No
Number of breakdowns
1.
…………………………….
2.
……………………………
3.
…………………… etc (use additional sheets)
4. How many times has each monitor broken down in its lifetime?
Monitor No
Years in service
1.
…………………………….
………………….
2.
……………………………
…………………..
3.
5. What are the common faults?………………………………………………………
………………………………………………………………………………………….
……………………………………………………………………………………………………
……………………………………………………………………………………………………
……………………………………………………………………………………………………
………………………………………………………….
127
6. What spares have been replaced in the past year?
Monitor No
Description of spares used in one year
total cost of those spares
……1……………………………………………………………………………………
…………………………………………………………………………………………..
……2……………………………………………………………………………………
…………………………………………………………………………………………..
……3……………………………………………………………………………………
……etc…………………………………………………………………………………
( Use additional sheets where necessary)
7. Is preventive maintenance action carried out? Yes……… No………………….
8. What type of preventive action is carried out?
Cleaning………… Resoldering……….. Observe and log performance……..
Scheduled preventive maintenance according to manufacturer‟s service instructions………
Other(specify)…………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
………………………………………………………
SECTION B:
9. Please describe the type and quantity of video cameras in your section/department/station.
Manufacturer
Model No.
Quantity
……………………………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………………….
…………………………………………………………………………………………
(Use additional sheets where necessary)
10. For how many hours are these cameras used on average per day? (1 day = 24 hours)
…………………………………………………………………………………………..
11.
How many times has each camera broken down in the past year?
Camera No
1.
…………………………….
2.
……………………………
3.
12.
How many times has each camera broken down in its lifetime?
128
Camera No
1.
2.
3.
Years in service
…………………………….
………………..
……………………………
………………….
…………………… etc (use additional sheet)
13. What are the common faults?
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
…………………………………………………………………………………………………………
………………………………………………………………………………………………………
………………………………………………………………………………………….
Camera No
……1……………………………………………………………………………………
…………………………………………………………………………………………..
……2……………………………………………………………………………………
…………………………………………………………………………………………..
……3……………………………………………………………………………………
……etc…………………………………………………………………………………
15.
16.
Is preventive maintenance action carried out? Yes……… No………………….
What type of preventive action is carried out?
Cleaning………… Resoldering……….. Replacement of parts…………
Observe and log performance…… Scheduled preventive maintenance according to
manufacturer‟s service instructions………
Other(specify)…………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
……………………………………………
SECTION C:
17.
Please describe the type and quantity of VTRs (video tape recorders) in your
section/department/station.
Manufacturer
Model No.
Quantity
……………………………………………………………………………………………………
………………………………………………………………………………
………………………………………………………………………………………….
…………………………………………………………………………………………
129
………………………………………………………………………………………….
18. For how many hours are these VTRs used on average per day? (1 day = 24 hours)
…………………………………………………………………………………………..
19.
How many times has each VTR broken down in the past year?
VTR No
1.
…………………………….
4.
……………………………
5.
20.
How many times has each VTR broken down in its lifetime?
VTR No
Years in service
1.
…………………………….
………………..
2.
……………………………
………………….
3.
…………………… etc (use additional sheet)
What are the common faults?………………………………………………………
……………………………………………………………………………………………………
……………………………………………………………………………………………………
……………………………………………………………………………………………………
……………………………………………………………………………………………………
……………………………………………….
21.
VTR No
……1……………………………………………………………………………………
…………………………………………………………………………………………..
……2……………………………………………………………………………………
…………………………………………………………………………………………..
……3……………………………………………………………………………………
……etc…………………………………………………………………………………
23.
24.
Is preventive maintenance action carried out? Yes……… No……………
Cleaning…. Resoldering……….. Lubrication………replacement of parts…….
Observe and log performance ………. Scheduled preventive maintenance according to
manufacturer‟s service instructions………
130
Other
(specify)………………………………………………………………………………………
…………………………………………………………………………………………………
…………………………………………………………………………………………………
……………………………………………………..
SECTION D: (This section is to help us understand the efforts put into ensuring reliability of
equipment in form of expenditures on staff)
25. What is the total size of station staff?
……………………………………………………………………………………….
26. What is the total size of technical staff?
………………………………………………………………………………………..
27. How much money in, total, does the technical staff receive in form of wages in one month?
………………………………………………………………………………………..
Thank you for your cooperation.
Interpretation of the questionnaire
Question 1,9,17
The answers to these questions were used to calculate the cost of spares per year for video tape
recorders, video monitors and video cameras (see table 3.20.4, 3.20.5, and 3.20.6). Thus average
cost of spares per unit per year was defined as:
Total cost of spares used by all similar units per year
Total number of units assessed
Question 2,10,18
The answers to these questions were used in the calculation of TBF (Time Between Failures) in
section 3.20, thus:
TBF = 365 x number of years equipment has been in service x hours it is in use per day
Total number of failures during equipment‟s service life
131
Question 3,4,11,12,19,20
The answers to these questions were used in the calculation of TBF (Time Between Failures) in
section 3.20 (see above).
Question 5,13,21
The answers to these questions were used answer research question 2 in section 4.2.2.
Question 6,14,22
The answers to these questions helped us calculate the average cost of spares per machine per year
(As part of the total maintenance cost).
The average cost of spares for one machine for one year (a yardstick for comparison between TV
stations) , for example, the average cost of maintaining a VTR in UTV was compared with average
cost of maintaining a VTR in WBS (see tables 3.20.4, 3.20.5, 3.20.6 and fig. 3.20.7.1).
Question 7,8,15,16,23,24
The type of maintenance strategy involved was used to answer research question 4 in section 4.2.4
and research question 2 in section 4.2.2.
Question 25,26,
This was used to assess maintenance costs related to staff as a ratio i.e. ratio of maintenance staff to
total staff ( see section 1.5)
Question 27
This was used to assess maintenance costs related to staff as money expended in form of wages. A
comparison was made between average maintenance staff wages for UTV and WBS (see fig
3.20.7.3). In the case of WBS 4,600,000/= was divided among nine staff. In the case of UTV
12,344,810/= was divided among 56 staff.
132
ANNEX 3: ANSWERS TO QUESTIONNAIRE THAT WAS SENT TO WBS
The Following is the data that was obtained from WBS TV.
Legend: Q:
A:
Question
Answer
SECTION A:
Q: Please describe the type and quantity of video monitors in your station.
1. A:
Manufacturer
JVC
Quantity
2
Vista
Model No.
TM –150 PSNK
14 inches
PVM 91CE
21 inches
TVM9B 9 inches
Melford
Philips
DU 6 –20C
LHD 6200
10
1
Sony
12
4
Q: How many hours are these monitors switched on per day? (one day = 24hours)
2
A: Twenty four (24) hours.
3.
Q: How many times has each monitor broken down in the past year?
3A:
JVC TM –150 PSNK
Monitor No
1
2
Number of breakdowns in the past year
1
2
SONY PVM- 91CE
Monitor No
1
2
2
2
133
3
4
5
6
7
8
9
10
11
12
2
5
0
1
1
3
4
3
0
1
VISTA TVM9B
Monitor No
1
2
3
4
1
4
1
2
MELFORD DU6-20C
Monitor No
1
2
3
4
5
6
7
8
9
10
0
0
1
0
1
1
1
1
1
0
PHILIPS LHD 6200
Monitor No
1
1
4
Q: How many times has each monitor broken down in its service life?
134
A:
JVC TM –150 PSNK
Monitor No
Years in service
1
2
4
5
SONY PVM- 91CE
Monitor No
Years in service
1
2
3
4
5
6
7
8
9
10
11
12
6.25
6.25
5.17
5.17
6
6
6
4.25
3.17
6
6
5
VISTA TVM9B
Monitor No
Years in service
1
2
3
4
4.67
4.67
4.67
4.67
MELFORD DU6-20C
Monitor No
Years in service
1
2
3
4
5
5
5
4
135
Number of
breakdowns
2
4
Number of
breakdowns
2
7
3
8
6
3
3
4
8
6
0
3
Number of
breakdowns
6
5
7
4
Number of
breakdowns
0
0
2
1
5
6
7
8
9
10
3
6
6
6
6
6
2
2
2
1
2
0
PHILIPS LHD 6200
Monitor No
Years in service
1
3
Number of
breakdowns
2
5
Q: What are the common faults?
5
A:
Manufacturer
Model No.
JVC
TM –150 PSNK
14 inches
Common faults
Sony
PVM 91CE
21 inches
No vertical scan caused by shorted vertical i.c.
Vertical fold over of picture.
No picture (blank screen) caused by open circuit .
Heavy leakage of smoothing capacitor in power supply.
Vista
TVM9B 9 inches
EHT start up problems caused by shorted HOT transistor.
Low EHT (dark screen).
Presence of retrace lines on picture caused by low Gz voltage.
Horizontal and vertical rolling of picture (loss of sync).
Failure of filter capacitor in power supply.
Lack of contrast.
Black and white bars in picture.
136
Melford
DU 6 –20C
Intermittent operation.
Picture distortion.
No picture.
Lack of contrast.
Philips
LHD 6200
6 (a)
Insufficient horizontal width.
Insufficient vertical height.
No scan (no raster)
Q: What spares have been replaced in the past year? (Conversion rate: 1USD: 1800Ushs)
JVC TM –150 PSNK
Monitor No
Spares replaced in the past year
1
2
Total cost of
those spares
Ushs
7000/=
Total cost of
those spares
USD
3.89
12,000/=
6.67
1pcs flyback transformer.
1pcsFocus control potentiometer.
25,000/=
10,000/=
13.89
5.56
Sub Total
54,000/=
30.01
2pcs smoothing capacitor in power
supply.
6pcs horizontal output transistor.
SONY PVM- 91CE
Monitor
No
1
1pcs vertical output i.c.
1pcs dropper resistor for vertical output
i.c. D.C. voltage.
2
3
Total cost of
those spares
Ushs
3,500/=
500/=
Total cost of
those spares
USD
1.94
0.28
6pcs video output transistor.
4,500/=
2.5
6pcs fusible resistor.
1pcs main smoothing capacitor in
power supply.
2,000/=
3,500/=
1.11
1.94
137
4
6,000
3,000
3.33
1.67
None
500/=
2000/=
500/=
None
0.28
1.11
0.28
-1pcs bridge rectifier
- 1400k series capacitor,100uf 6.3V
supply.
4pcs rectifier diodes.
4,500/=
2,000/=
3,500/=
2.5
1.11
1.94
4,000/=
2.22
10
1pcs chopper transistor.
1pcs fuse.
2,000/=
5,00/=
1.11
0.28
11
None
None
None
12
1pcs resistor ½ w.
3,500/=
250/=
1.94
0.14
Sub Total
46,250/=
25.68
Total cost of
those spares
USD
1.39
5
6
7
8
9
3pcsVision output transistor
2pcs Vertical i.c.
None
1pcs +B line voltage fuse.
1pcs horizontal output transistor.
2pcs resistors 1/4W.
VISTA TVM9B
Monitor
No
1
1pcs Capacitor 100uf 25V.
Total cost of
those spares
Ushs
2,500/=
2
6pcs resistors. (R663, 100R)
6,000/=
1,800/=
3.33
1.0
3
25,000/=
13.89
4
3pcs dropper resistors.
900/=
0.5
Sub Total
36,200
20.11
138
MELFORD DU6-20C
Monitor
No
1
2
3
None
None
8pcs contrast control variable resistors.
Total cost of
those spares
Ushs
None
None
12,000/=
4
5
None
1pcs vision output transistor.
None
2,000/=
None
1.11
6
50,000/=
27.78
7
6pcs resistors.
6pcs capacitors.
1,800/=
4,500/=
3,500/=
1.0
2.5
1.95
8
supply,150uf 400V.
1pcs fuse.
3,500/=
1.94
300/=
0.17
2pcs biasing resistors.
1,000/=
0.56
None
None
78,600/=
43.68
Total cost of
those spares
Ushs
2,000/=
900/=
2,900/=
Total cost of
those spares
USD
1.11
0.5
1.61
9
10
None
Sub Total
PHILIPS LHD 6200
Monitor
No
1
6.
1pcs Horizontal output transistor
3pcs resistor
Sub Total
Q:
Is preventive maintenance action carried out?
139
Total cost of
those spares
USD
None
None
6.67
6.
A:
Yes.
7.
Q:
7.
A:
cleaning and resoldering.
SECTION B:
Q: Please describe the type and quantity of video cameras in your station.
A:
Manufacturer
Sony
Panasonic
Sony
JVC
Model No.
DSR – PD150P
NV-MX500
CVR 300AP
GY –DV 500E
Quantity
2
4
3
3
Q: For how many hours are these cameras used on average per day? (1 day = 24 hours)
10.
A: 12 hours.
Q: How many times has each camera broken down in the past year?
11.
A:
DSR – PD150P
Camera No
1
2
0
1
NV-MX500
Camera No
1
2
3
4
1
1
0
0
CVR 300 AP
Camera No
1
2
0
1
140
3
1
GY –DV 5000E
Camera No
1
2
3
2
0
1
Q: How many times has each camera broken down in its lifetime?
12.
A:
DSR – PD150P
Camera No
Years in service
1
2
1
1
Number of
breakdowns
0
1
NV-MX500
Camera No
Years in service
1
2
3
4
2
2
2
2
CVR 300 AP
Camera No
Years in service
1
2
3
6
6
6
GY –DV 5000E
Camera No
Years in service
1
2
3
2.67
2.67
2.67
141
Number of
breakdowns
3
1
0
0
Number of
breakdowns
1
2
2
Number of
breakdowns
3
1
3
13.
13.
A:
Manufacturer
Model No.
Sony DVCAM
DSR-PD150P
Panasonic
NV-MX500
Common faults
One of the three RGB colours missing from CCD chip.
Tape jammed inside camera (jammed mechanism)
Presence of tracking lines on playback video.
Sony CVR-300AP
Video heads worn out (noisy video playback).
Zoom in and out fault.
No audio on recording and playback.
JVC GY-DV5000E
Power supply problems.
Tape loading malfunction.
No audio during recording and playback.
14 (a) Q: what spares have been replaced in the past year?
14 (a) A:
DSR – PD150P
142
Camera No
Spares replaced in the past
year
1
2
None
CCD assembly
Sub Total
Total cost
of those
spares
Ushs
None
1,800,000/=
Total cost
of those
spares
USD
None
1,000
1,800,000/= 1,000
NV-MX500
Camera No
year
1
Total cost
of those
spares
Ushs
720,000/=
Total cost
of those
spares
USD
400
540,000/=
300
None
None
None
1,260,000/=
None
700
Total cost
of those
spares
Ushs
None
1,224,000/=
Total cost
of those
spares
USD
None
680
1,800,000/=
1000
3,024,000/=
1680
Capstan motor
2
Video head
3
4
CVR 300 AP
Camera No
1
2
None
None
Sub Total
year
None
Zoom lens gears
3
Video head
Sub Total
GY –DV 5000E
Camera No
year
143
Total cost
of those
spares
Ushs
Total cost
of those
spares
USD
1
Power supply Board.
2
1,224,000/= 680
None
none
None
1,224,000/= 680
Sub Total
15.
Q:
15
A: Yes
16.
Q: What type of preventive action is carried out?
16.
A: cleaning and lubrication.
SECTION C:
Q: Please describe the type and quantity of VTRs (video tape recorders) station.
17.
A:
Manufacturer
Model No.
Quantity
Sony
BVW 75P
1
Sony
PVW 2800P
5
Panasonic
DVC-PRO AJ-D750
1
JVC
DV/VHS
6
SONY
UVW 1800P
6
18.
18.
Q: For how many hours are these VTRs used on average per day? (1 day = 24 hours)
A: 16 hours
19.
19.
Q: How many times has each VTR broken down in the past year?
A:
BVW 75P
VTR No
1
2
PVW 2800P
144
VTR No
1
2
3
4
5
3
4
2
1
2
AJ D750
VTR No
1
1
1
1
JVC DV/VHS
VTR No
1
2
3
4
5
6
1
2
1
1
0
3
UVW 1800P
VTR No
1
2
3
4
5
6
3
4
1
6
6
2
Q: How many times has each VTR broken down in its lifetime?
20.
A:
BVW 75P
VTR No
Years in service
1
5
Number of
breakdowns
11
Years in service
Number of
PVW 2800P
VTR No
145
1
2
3
4
5
4
4
3.5
3.5
3.5
AJ D750
VTR No
Years in service
1
2
1
1.5
DV/VHS
VTR No
Years in service
1
2
3
4
5
6
3
3
3
3
3
3
UVW 1800P
VTR No
Years in service
1
2
3
4
5
6
2
2
1.5
3
3
2
21.
A:
146
breakdowns
10
13
6
4
5
Number of
breakdowns
1
1
Number of
breakdowns
3
4
2
6
1
5
Number of
breakdowns
3
2
2
6
5
3
Common faults
Sony Betacam SP
PVW 2800P
Poor rec/playback picture due to worn out video head.
Cassette compartment jammed.
Capstan motor jammed.
Panasonic DVC
PRO AJ D750
Cassette compartment failure.
Loading mechanism failure.
Video head worn out.
JVC DV/VHS
Power supply problems.
DV cassette compartment and power supply problems.
Sony Betacam SP
UVW 1800P
Cassette compartment failure.
Tape loading failure.
Capstan motor failure.
Video head recording and playback failure.
22 .
Manufacturer
Model No.
Sony Betacam SP
BVW 75P
Capstan trouble
Cassette compartment jammed.
Wrong tape tension.
Pinch roller worn out.
Q: What spares have been replaced in the past year?
22
.
BVW 75P
VTR No
1
A:
year
- 1pcs video head
- 1pcs cassette compartment
Total cost
of those
spares
Ushs
1,008,000/=
972,000/=
Sub Total
1,980,000/= 1100
PVW 2800P
147
Total cost
of those
spares
USD
560
540
VTR No
year
Total cost of
those spares
UShs
1
2pcs video head DBR40BR
- 1 pcs cassette compartment
1,800,000/=
Total cost
of those
spares
USD
1,000
2
1pcs threading mechanism
assembly
2 pcs video head
1pcs AC connector
1,800,000/=
4,500,000/=
1,000
2,500
1,800,000/=
20,000/=
1,000
11.11
1,800,000/=
1,000
900,000/=
180,000/=
500
100
3
1pcs cassette compartment
1 pcs video head DBR 40BR
4
1pcs tape loading motor
5
- 2pcs video head DBR 40BR 1,800,000/=
Sub Total
DVCPRO AJ D750
VTR No
1000
14,600,000/= 8,111.11
year
Total cost
of those
spares
Ushs
Total cost
of those
spares
USD
1pcs cassette assembly
- 1pcs video head
Sub Total
1,440,000/= 800
720,000/=
400
2,160,000/= 1,200
year
Total cost
of those
spares
1
2
DV/VHS
VTR No
148
Total cost
of those
spares
1
1pcs DV mechanism
assembly.
1pcs capstan motor
Ushs
USD
1,260,000/= 700
594,000/=
330
2
1pcs pinch roller
1pcs belt
3,000/=
1,000/=
1.67
0.56
3
- 1pcs tape loading belt
1,000/=
0.56
4
1pcs VHS video head
1pcs DV power board
None
70,000/=
720,000/=
None
38.89
400
None
1pcs pinch roller
1pcs DV mechanism assembly
Sub Total
6,000/=
3.33
1,080,000/= 600
3,735,000/= 2,075.01
year
Total cost of
those spares
Ushs
1
1pcs video head DBR-40-BR
900,000/=
Total cost
of those
spares
USD
500
2
1,260,000/=
700
3
- 1pcs pinch roller assembly
X-3166-040-04
- 1pcs mechanism assembly
7,200,000/=
4,000
1pcs cassette compartment.
1pcs video head DBR-40-BR
1,800,000/=
1,000
4
900,000/=
1,260,000/=
500
700
180,000
100
5
6
UVW 1800P
VTR No
5
6
- 1pcs pinch roller assembly
X-3166-040-04
1 pcs loading motor.
1pcs cassette compartment
1,800,000/= 1,000
15,300,000/= 8,500
Sub Total
23.
23.
Q:
A: yes
24.
Q: What type of preventive action is carried out?
149
24.
A: Cleaning, resoldering, lubrication, replacement of parts and scheduled preventive
maintenance according to manufacturers service instructions.
SECTION D
25. Q: What is the total size of station staff?
25. A: One hundred and twenty (120) people.
26. Q: What is the total size of technical staff?
26 . A: Nine (9) people.
27. Q: How much money in, total, does the technical staff receive in form of wages in one
month?
27.
A: Four million, six hundred thousand only.
ANNEX 4: SPARES LISTS
150
SPARES LIST FOR SONY UMATIC SP VIDEO CASSETTE RECORDER MODEL No
BVU950P
No
Description
Sony Part Number
Cost in USD
Upper video head drum assembly
1
DUR 44R
A-6709-617-A
333.32
2.
Pinch Roller Assembly
A-6750-223-A
30.48
3.
Belt for LM (loading Motor)
3-653-387-00
1.90
4.
Box block assembly gear/gear box
A-6750-224-A
22.22
5.
Roller block assembly drawer
A-6746-050-D
53.17
Ring block assembly/Threading ring
6.
assembly
A-6750-222-A
96.50
7.
Roller ring
3-668-963-03
1.90
8.
Flying erase brush assembly
A-6709-619-A
60.32
TU (take up) reel assembly/reel
9.
table
1-6739-080-A
12.06
10.
Full erase head
8-825-544-20
50.16
A-6709-616-A
565.06
1-570-117-11
6.35
Lower video head drum assembly
11.
DUH 44 BR
Toggle switch (AC power 250V
12.
50HZ)
13.
Head ACE (audio CTL head)
14.
Pinch Solenoid/solenoid plunger
1-454-416-31
15.
Belt Square (belt for gear box)
3-672-737-01
1.90
1-413-307-23
53.33
85.71
Switched mode power
16.
supply/switching regulator (UR21B)
SPARES LIST FOR SONY UMATIC SP VIDEO CASSETTE RECORDER MODEL No
VO9850P and VO9800P
No
1
Description
Belt, LM (belt for cassette
Sony Part Number
3-653-387-00
151
Cost in USD
1.90
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
compartment motor)
Reel motor (motor DC
FN30T26NIE)
Pinch roller
Electrolytic Capacitor 100uf 20%
16v
Upper drum DUR 46R (for
VO9800P)
Box block assembly gear (gear box)
Belt square (belt for gear box)
Upper drum DUR44R (for
VO9850P)
Power socket inlet (3 pins)
Ring block assembly (threading
ring)
MD60 circuit board
Dial block assembly, search
(shuttle/jog mechanism)
Belt 67x2 (reel belt)
Capstan motor (motor DC BHF –
1915B)
PS 503 link I.C. 0.6 A
Cassette up block assembly
Lower drum motor assembly DUH
46BR for VO9800P
Lower drum motor assembly DUH
44BR for VO9850P
Switch toggle (AC power)
Audio/CTL head
AC –98 board
Idler assembly FF
8-835-409-01
A-6750-223-A
53.97
30.48
1-126-101-11
A-6709-637-A
A-6750-224-A
3-672-737-01
207.61
22.22
1.90
A-6709-617-A
1-560-222-11
333.32
5.00
A-6750-222-A
A-6727-083-A
96.50
700.00
A-6734-238-B
3-668-785-00
46.35
1.90
8-835-258-02
1-532-679-00
A-6751-391-B
163.80
1.00
107.93
A-6709-682-A
450.78
A-6709-675-A
1-570-117-11
8-825-578-22
565.06
6.35
85.71
X-3646-026-0
2.54
ANNEX 5: THE UGANDA BROADCASTING CORPORATION
The Uganda Broadcasting Corporation (UBC) was formed after the merger of Radio Uganda and
Uganda Television in November 2005. It is a 100% government owned corporation formed under
152
Uganda‟s Corporation laws. The corporation was formed after the acquisition and analysis of data
for this report.
The corporation recruited some former UTV and Radio Uganda Staff together with new staff from
Uganda Broadcasting council and private media stations and houses.
The structure of the corporation is dynamically evolving. The current simplified structure of the
Engineering section is shown below
Operations Manager
Head of Engineering
Studios and
production
engineer
Transmission and
communications
engineer
Technicians
Technicians
FIG. A5.1
Maintenance and
projects engineer
Technicians
ORGANISATIONAL STRUCTURE OF UBC ENGINEERING SECTION
Organisation of maintenance
Maintenance work is spearheaded by the maintenance and projects engineer.
153
Challenges of maintenance

Ten very old TV transmitters dating back to the early 1980 s and even older Medium
wave and short wave transmitters. Only one new TV transmitter has been procured since
the formation of the corporation.

Satellite uplink equipment dating back to 1999. One problem with the satellite
equipment has been the lack of funds to purchase spares. The other problem has been the
payment of satellite space segment rental costs amounting to USD 18,000 per month.

The corporation had to relocate from the UTV premises (July 2006) and have the TV
and radio studios at the former radio Uganda. A lot of equipment was damaged during
the relocation and the challenge is to have all this equipment repaired.

The Outside broadcasting TV van is more known for its excellent mechanical condition
but equipment used is borrowed from other sections. Management has concentrated on
giving it an external facelift by way of spraying the exterior. There are plans to buy a
new outside broadcasting van.

Post production and programme gathering equipment have been improved by purchase
of rechargeable batteries and some domestic DV cameras that are not robust but require
very careful maintenance.
ANNEX 6: ANALYSIS OF DATA FROM WBS TV
A6.1
Data for videocassette recorder BVW 75P
154
VTR No
1
Years in service Number of breakdowns
5
A6.2
VTR No
1
2
3
4
5
1
2
4
4
3.5
3.5
3.5
1
2
3
4
5
6
1
1.5
TBF
2336.00
1796.92
3406.67
5110.00
4088.00
10
13
6
4
5
Data for videocassette recorder AJ D750
TBF
5840
8760
1
1
Data for videocassette recorder DV/VHS
3
3
3
3
3
3
A6.5
VTR No
Data for videocassette recorder PVW 2800P
A6.4
VTR No
11
A6.3
VTR No
TBF
2654.55
TBF
5840.00
4380.00
8760.00
2920.00
17520.00
3504.00
3
4
2
6
1
5
Data for videocassette recorder UVW 1800P
TBF
155
1
2
3
4
5
6
2
2
1.5
3
3
2
A6.6
Monitor No
1
2
1
2
3
4
5
6
7
8
9
10
11
12
3893.33
5840.00
4380.00
2920.00
3504.00
3893.33
Data for video monitor JVC TM –150 PSNK
4
5
A6.7
Monitor No
3
2
2
6
5
3
TBF
17520
10950
2
4
Data for video monitor SONY PVM- 91CE
6.25
6.25
5.17
5.17
6
6
6
4.25
3.17
6
6
5
A6.8
TBF
27375
7821.429
15096.4
5661.15
8760
17520
17520
9307.5
3471.15
8760
0
14600
2
7
3
8
6
3
3
4
8
6
0
3
Data for video monitor VISTA TVM9B
156
Monitor No
1
2
3
4
4.67
4.67
4.67
4.67
A6.9
Monitor No
1
2
3
4
5
6
7
8
9
10
TBF
6818.2
8181.84
5844.171
10227.3
6
5
7
4
Data for video monitor MELFORD DU6-20C
5
5
5
4
3
6
6
6
6
6
TBF
0
0
21900
35040
13140
26280
26280
52560
26280
0
0
0
2
1
2
2
2
1
2
0
A6.10 Data for video monitor PHILIPS LHD 6200
Monitor No
1
3
TBF
13140
2
157

(Mak) A dissertation submitted to the school of graduate studies in

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