Production Management I

Transcription

Production Management I
- Lecture 9 Lean Production – Production Systems
Contact:
Dipl.-Ing. A. Gulden
[email protected]
WZL R.516
Tel.: 80-28094
© WZL / IPT
Lean Production – Production Systems
Seite 1
Lecture 9
Content Lecture 9
1.
Directory
L9 page II
2.
Summary
L9 page III
3.
Glossary
L9 page IV
4.
Lecture
Highlights
L9 page 1
The way to Lean Production
L9 page 2
Lean Thinking: Orientation of value from customers´ view
L9 page 4
A typical factory…
L9 page 5
Lean Production begins at the customer
L9 page 6
Role model Toyota Production System
L9 page 8
Production smoothing as a base for stable processes
L9 page 9
Process synchronization as a base of capacity
L9 page 10
Kanban for autonomous material control acc. to the pull principle
L9 page 11
Empowerment and teamwork
L9 page 12
Lean Automation – „Autonomation“
L9 page 13
Poka Yoke for failsafe working
L9 page 14
The 7 types of wasting in the Lean Production
L9 page 15
Visual management as a control and leading instrument
L9 page 16
Value Stream design: The current tool in Lean Production
L9 page 18
Prozess optimisation with the value stream principle
L9 page 19
6S – Order & Cleanlineless
L9 page 20
Optimized sidewalks & utilization of capacity in U-Layout
L9 page 21
Optimization of setup work
L9 page 22
KVP – workshops in the production
L9 page 23
continuous improvement (Kaizen)
L9 page 24
Lean Production: a challenge for the culture in the enterprise
L9 page 25
Production Systems in different enterprises
L9 page 26
List of literature
L9 page 27
L9 page II
Lecture 9
Summary
Based on cost pressure and restrictions, different management concepts have been discussed
and implemented in producing enterprises. In particular the automobile industry takes in pioneer
role the discussion about integrated order systems for the different functions.
In the area of production, producing enterprises use production systems to harmonize their
activities in production and to integrate there activities in a comprehensive concept. Production
systems describe the constitutional structure of the whole production organization and contain the
representation off all concepts, methods and tools, which constitute the effectiveness and
efficiency of the production flow. They consort and standardize the sequences of functional units
in the production and form the platform for the continuous advancement and optimization at the
same time.
Production systems are normally adapted to the needs and characteristics of the enterprises;
essential similarities are the methods, procedures and devices. Considerably modern production
systems orient themselves at principles of the Lean Production. The term “Lean Production” was
affected in the team by Jim Womack, Dan Jones and Dan Ross in the International Engine
Vehicle program. It is known as the “MIT Study”. The underlying paradigms are process
orientation, partaken-cooperative work system design and continuous improvement.
In the first part of the lecture Production Systems – Lean Production the Lean Production
principle is fundamentally introduced. Afterwards the systems and methods of Lean Production
will be presented. Last, possibilities for implementing Lean Production systems will be described.
L9 page III
Lecture 9
Glossary
5M
Method to avoid failures, regarding: Humans, machines, material, method and measurement.
6S
Corresponds to the method 6A, is based however on Japanese terms. 6 S stand for … Seiri
(clearance) … Seiton (arrange) … Seiso (cleanlineless) … Seiketsu (tidiness) … Shitsuke
(discipline) and Shukan (adaption)
Andon
Tool for sending information in case of arising problems. Staff member, who discover an error,
release a signal, in order to call for assistance (master, colleague) even. Examples are: Andon
cord or -button: Thus staff members can stop a band or plant. Andon display panels, inform
about the current state of the production. The display refers with light signals to errors at the
machine / the system. It serves as central display and should be visible for all staff members.
Heijunka [jap.]
Production smoothing/ levelled production
Jidoka [jap.]
also autonomation (Auto-NO-Mation). Man less machine operation
Just-in-time (JIT)
Principle for controlling the material and information flow along the entire process chain. The
correct part is made available in the correct quality (zero error) to the correct time (exactly, if it is
needed) in the correct quantity (a part) of the correct place (where it is needed). JIT supports the
pull-principle. Stock should be avoided. In addition it requires a flexible manufacturing with small
lot sizes and KANBAN system.
KANBAN
The meaning of Kanban is translated card. It is a method to control the material flow. If the stock
level is below minimum level, the supply is ordered by card or voucher. Kanban is also used for
implementing the pull principle.
KAIZEN
Change (KAI) to the good one (ZEN), thus continuous improvement. The use of the creative
potential of the employees is important.
Lean Production
Optimized processes, which is almost free from waste
PDCA-Circle
Quality and improvement control loop according to the principle: plan, do, check, action
Poka-Yoke [jap.]
Poka: random, accidental mistake, Yoke: prevention of mistakes
SMED [engl.]
Single Minute Exchange of Die: setting-up in less than 10 minutes.
Value stream analysis/value stream design
The value stream covers all activities and processes (value added and not value added), which
are necessary to illustrate a product or service from the incoming orders to the distribution
descriptive. Part of the value stream analysis is to retrace the process along the value stream.
The method serves for the identification of weak points/waste and for process improvement. The
emphasize of the purpose is on the reduction of the turn-around time and the inventories.
L9 page IV
Lecture 9
Lecture highlights
Basic principle and thought pattern in the Lean
Production
Methods and concepts in Lean Production
(at Toyota production system),
particularly
–
–
–
–
Production smoothing
Process synchronisation (Adjustment of capacity)
Pull-control with Kanban
7 kinds of waste
Implementation to Lean Production: value stream design
© WZL / IPT
page 5
Notes on figure:
L9 page 1
Lecture 9
The way to Lean Production
Historical personalities
Japanese development
Cause effect
diagram
Extensive introduction
Lean Production
Beginning of the
Toyota production
system
1910
1920
Standardization of
Work (Taylor)
1930
1940
1950
1960
Kaizen
1970
1980
1990
2000
Lean Production
Demings
„14 points“
Control of Quality
(Radford 1917,
1922)
Quality Control
FMEA
Total Quality
Control
(Sheward)
Western development
© WZL / IPT
page 6
Notes on figure:
In the eighties, due to the upcoming globalization, Western European and American industrial
enterprises have been hit at a point they never expect, namely in factory. Analysis showed the
superiority of Japanese production concepts, which the locals never achieved. That is why in
Japan new products were brought to the market in half of the time and with half of the costs. At
the same time the investment in tools and personal equipment in manufacturing sank likewise.
First explanation about the Japanese success have been very fragmentary in the begining. The
long work times, the small wages and the high automation found their precipitation in scientific
and popular-scientific papers. Intensive discussions were made in the media. The publication by
Womack, Ross and Jones at the Massachusetts Institute of Technology (MIT) with the title: “the
second large revolution in the large automobile industry” obtained only the Japanese concept a
comprehensive picture of the management for a selected industry. The basis was a comparative
study about the western European, American and Japanese automobile industries. The basics of
such a succeed were the MIT-study: a comprehensive inclusion of the suppliers, the construction
of production-friendly cars, the better training for the workers.
The differences were so serious for the European and American competitors that Womack, Jones
and Roos spoke about the second industrial revolution. The Japanese enterprises affected the
term “Lean Production”, because they reached with less more. Now the term is also used in
different divisions as “Lean Development”, “Lean Management” etc.
The mechanical-technological attempt by Taylor was the first industrial revolution. The production
improvement was reached by the strict separation of the individual work steps, the strict
separation from implementing and administering work and by the change from the handicraft to
the mass production of few versions. Thereby the circulation of the working sphere and the
consumer habits were released world-wide seriously. Rightfully this circulation is called the first
industrial revolution.
L9 page 2
Lecture 9
Contents
The principle of Lean Production
Systems und methods of Lean Production
Conversion to the Lean Production principle
© WZL / IPT
page 7
Notes on figure:
L9 page 3
Lecture 9
Lean Thinking: Orientation of value from costumers´ view
Staff member and culture
processes
How are weak points
recognized and used?
For which processes
does the costumer pay?
Which role does the
individual coworker take?
What is added value,
what is not?
What does
the customer
call „value“?
customer
process
C
process
B
Organisation
Who can make the best decision?
Who recognizes the main problem best?
process
A
supplier
Supplier management
How can processes be
synchronized in networks
Are the capacity and qualification optimally uses
in Anl. an Womack/ Jones: Lean Thinking, 1996
© WZL / IPT
page 8
Notes on figure:
The origin of Lean Thinking is basically the value. Value is created by the manufacturers. From
the customers point of view, this is the only reason for the existence of manufacturers. Value can
only be defined by the final consumer and relies on the value of the specific product (or service)
and is basis for the price consumers are willing to pay for the product on the market. This is why
manufacturers have to focus on what increases the value of its products and are forced to
diminish processes which do not generate surplus value.
The first step in lean thinking is to understand what value is and what activities and resources are
absolutely necessary to create that value. Once this is understood, everything else is waste.
L9 page 4
Lecture 9
A typical factory …
a Batch size
formation does not
correspondent to the
costumer demand
a Central planning
of all processes
PPS
customer
Daily
oder
supplier
a Rare delivery of
large quantities
a Bad tuning of
the
achievement
Weekly planning
Daily
delivery schedule
Supermarket
manufacturing
Manufac.
a Double step of
warehouse
3 days
14 days
a High stocks
∅ 21
days
HRL
50 days
Supermarket
assembly
forwarding
assembly
Montage
14 days
2 days
forwarding
1,5 days
a Multiple handling
1 hour
Turn-around
time =
125 days
a Push-controlling
© WZL / IPT
page 9
Notes on figure:
With help of a value stream, individual processes, stock levels and process durations can be
illustrated graphically. Entrapments of the value stream are emphasized with so called Kaizenflashes; entrapments can be e. g. very long, unnecessary wait times, which in Lean Thinking
corresponds to muda (wastage).
The figure shows a possible value stream of a producing enterprise: Optimization of such a value
stream is often organized as workshops integrating all responsible areas for generating
improvement activities. The simple “Rich Picture” symbols help to illustrate the important value
stream elements in a simple manner.
L9 page 5
Lecture 9
Lean Production begins at the customer
Orientation at the
customer demand
Optimization of
the own value stream
Aspire
perfection
P
D
A
customer
Value definition from
view of customer
Definition of the „tact“ of
demand
Definition of the intention
of the value stream
Planning of buffers and
decoupling interfaces
C
Continuous flow
Synchronisation of the circle
time
Pull-Controlling and FIFO
Production planning in
customer-mix
Elimination of 7 kinds
of waste
Standardisation and
continuous improvement
Fast retooling
Autonomous maintenance
Protection against errors
Production without staff
Supplier integration
…
ref. to D. Tapping: Value Stream Management, 2002
© WZL / IPT
page 10
Notes on figure:
L9 page 6
lecture 9
Contents
Systems and methods of Lean Production
Conversion to the lean Production Principle
© WZL / IPT
page 11
Notes on figure:
L9 page 7
lecture 9
Role model Toyota Production System
4
Empowerment &
teamwork
Highest quality, lowest cost, shortest time
Just-in-Time
Jidoka
3
Kanban
control
Stop and report
deviation
Continuous flow
cycle length
Pull-System
Separating manual &
automatic work
2
5
Lean Automation:
Autonomation
6
Poka Yoke:
error safety
Process
synchronisation
Heijunka
Standardising
Kaizen
Stability
1
Need smoothing
7
7 types of
wasting
8
Visual Management
Source: Toyota
© WZL / IPT
page 12
Notes on figure:
In the fifties the Japanese car manufacturer Toyota turned out into a large crisis:
it was to small for the mass car production, because of the powerful competition it could not set a
foothold on international markets and on the tiny Japanese domestic market high numbers of
items were not to be set off; besides, political defaults made necessary investments more difficult.
On top of that money was lacking: workers had just obtained job tenures and thus, because of the
high labour costs, means for purchasing important tools were lacking. The corporation would
have gladly built cars according to tayloristic principles, but it could not afford a press line, so that
parts were manufactured on one press. Thus virtue arose from hardship and a philosophy from
dealing with insufficiencies. Instead of classically isolating the production steps and processing
them in sequence, Toyota built all decisive steps on the way to the product around this core.
Trough close interlocking of process steps and team work, turn-around times were shortened and
error ratios were reduced, thus considerably lowering costs. Quality is no longer a station – it is
part of every process. The integrated production method loosened the interdependencies of time,
quality and costs and broke trough the old vicious circle of tayloristic mass production. Up to that
time more products were built by means of faster work flow, meaning shorter process steps,
which inevitably led to higher complexity of work an so to higher costs. The Toyota Production
System broke this chain and revolutionized production all over the world.
Today the Toyota Production System and its methods are world-wide considered a bench mark
for producing enterprises.
L9 page 8
lecture 9
1) Production smoothing as a base for stable processes
Acquisition
Market demand
Production
Pull
Quantity
Buffer
Quantity
Time
Time
synchronized
supply chain
stable capacity requirement
uncoupling of short term
demand fluctuations
Pre-requisite: small lot size
Cycle time
Product A
Product A
Product B
Product B
t
Stock
Product A
after Drew: Journey to Lean, 2004
© WZL / IPT
t
Product B
t
Product B
Product A
t
page 13
Notes on figure:
In an ideal world, companies would build their products to order in exactly the sequence that it
received the orders. The reality is that variable work content or differences in the total amount of
time it takes to build different products makes this impossible and demands a compromise, which
is achieved through production leveling. In production leveling, the true demand is artificially
smoothed; thus stable and changeless working conditions are ensured. These are mandatory
premises for standardization and high capacity utilization.
The concept of production smoothing is to diminish as much as possible the quantity variance in
a production line. Although the demand for products can change widely e.g. because of seasonal
aspects thus affecting monthly production volumes, production smoothing allows daily production
volumes to remain constant.
L9 page 9
lecture 9
2) Process synchronization as a base for high capacity utilization
Initial state
70
Customer cycle
60
Waiting time
40
30
20
Customer cycle
50
„Pacemaker“
50
Cycle time 70
[min]
60
„Pacemaker“
Cycle time
[min]
Final state
40
30
20
10
10
Employee
0
A
B
C
D
E
Employee
0
AB
CD
E
Trough process load balancing capacity requirements are synchronised and
workload is optimized
Every process has only one bottleneck (pacemaker), this controls the entire
process: upstream as pull and downstream as FIFO-push
Source: Tapping: Value Stream Management, 2002
© WZL / IPT
page 14
Notes on figure:
Takt is the German term for the beat or rhythm of a piece of music. Takt time is defined as the
total available time for production divided by the total customer demand for that period.
Takt time is designed to optimise material flow in pursuit of Just-in-time delivery to the customer.
This is done by setting the pace of production at the rate of demand, thus eliminating the risk of
overproduction (which in the world Lean Production deems the worst type of waste since it hides
and also causes other types of waste).
Process synchronisation is used to balance work content in a continuous flow line, which often
has the effect of reducing the amount of labour needed to build a product. The normal approach
is to balance all but one of the workstations to Takt, leaving the remaining workstations
(Operation AB and E in the figure) with a lower work content. In the short term, this spare capacity
provides flexibility for dealing with any problems that occur during the production cycle.
Due to the fact, that customer demand varies significantly from period to period companies have
to revaluate Takt time in each period to ensure that customer demand is always met. As
rebalancing lines and retraining people often result in a massive efforts, adoptions should be
made no more than twice a year to ensure that changes are manageable.
L9 page 10
lecture 9
3) Kanban for autonomous material control according to the pull
principle
Regular customer
Production Kanban
Delivery Kanban
Finished parts stock
Finished parts stock
Customer
process
Kanban board:
defined
work in progress stock
Part or material ordering for
the lines
Warehouse for finished parts
Prefabrication lines
Material allocation at the lines
Assembly
Kanban
Prefabrication
Supplier
process
Assembly
Assembly line
Product
Part production
Kanban
Signal Kanban for
buffer stocks
Parts warehouse
Acquisition parts
Kanban
Source: Takeda 1996
© WZL / IPT
Suppliers
page 15
Notes on figure:
Kanban (or production Kanban) is a method of controlling a process or part of a process of a JiT
production.
Centre point of this control principle are the cards (kanbans), assigned to the product variants,
that trigger the production order. A kanban represents a certain lot (according to the packing unit).
At the end of the process there is a filing for the various kanban cards. The number of cards of a
product variant in this filing gives clue to the priority of the production of this variant. The card is
removed from the storage at the beginning of the production of a product variant an wanders with
the lot trough the process in a buffer storage to the end of the process. The customer of this
process takes his ware from the buffer and puts the kanban back in the filing. Because of the fix
number of cards a Kanban control method makes sense only for balanced production quantities.
Another version of the production Kanban is the transport Kanban. This controls the material
transport between warehouses and/or production sites.
Kanban is favourable for a JiT production because it complies with the demands of pull control,
demand driven production, small lot sizes and visualisation and is simple, clearly laid out and self
controlling.
L9 page 11
lecture 9
4) Empowerment and teamwork
Classic system
Efficiency trough formalization and
standardization
Tayloristic division of labour
Central planning & organizing
Execution and control parting
Example: Ford 1920
Autonomous working groups
Example: Volvo Uddevalla 1980
© WZL / IPT
Efficiency trough incentives and
involvement
Integration of surrounding field
activities
Job rotation
Capacitive levelling within the group
Standards as „Temporary Best
Practice“
page 16
Notes on figure:
A form of the decentralization particularly relevant for the operational organization in production
are team work concepts .
In production tasks are only accomplishable by means of intense interaction of more co-workers
of different qualifications. The thus resulting coordination effort is minimized by forming self
organized teams that can perform a specific task completely. Compared with a classic
organization, in which everyone receives exact description of work, in teamwork a task is
assigned to several persons, who reach the task fulfilment independently. Teamwork is usually
associated with incentive pay to balance the growing responsibility.
A typical trait of the various types of teamwork is the degree of autonomy. The first step is the
responsibility for one owns work and continues over training responsibility and responsibility for
indirect activities (machine maintenance) to personnel, meaning co-worker, responsibility.
Teamwork concepts took hold of almost the entire production field of the automotive industry.
Also more and more companies of the machine and facility building industry are switching over to
such work concepts.
L9 page 12
lecture 9
5) Lean Automation - „Autonomation“
Components
Examples
Elimination of idle travelling
Eliminate of Handling and Transport
Motion optimization (e.g. faster feed)
Maximize equipment
efficiency
Machine size should match product size
Workplace merging
Build cheaper
equipment
Match machines to the
flow
Simplify retooling
Error autonomy
Consideration for quantity proportion
In cycle times producing equipment
Splitting of internal and external retooling
Fast clamping fixtures
Outright production of GO parts
Machine stop at malfunction
Securing all machining steps
Source: Takeda 1995
© WZL / IPT
page 17
Notes on figure:
Autonomation is a process designed to allow a workforce to detect production problems quickly
and resolve them decisively. Its objectives are to improve equipment reliability, enhance product
quality and increase productivity. It consists of three elements:
– Detect and stop: The most effective method of detecting a fault or abnormality is to give the
responsibility to the people who operate the process.
– Alert: Once a problem has been detected, the process or the operator needs to alert the
team leader. This can be done verbally, by means of an Andon board (a display that
indicates production status), or via an audible alert.
– Root-cause problem solving: Even if it isn’t possible to rectify the root cause immediately,
it’s important to take action to contain the problem before the process is restarted. It may be
e.g. that an additional check needs to be made on every component until the source of an
intermittent fault upstream in the process has been identified and addressed.
L9 page 13
lecture 9
6) Poka Yoke for failsafe working
Poka Yoke
Failure safety
Trigger mechanisms
Contact
method
Fix value
method
Deviation from
geometrical
parameters
Deviation from the
number of work
steps
Regulation mechanisms
Step sequence
method
Intervention
method
Alarm
method
Group
identification
Controlling the
standard movement
sequence
Stop at
irregularities
Signals that point
to human error
Self control able
groups
Process
B
Part
Part holder
Process
A
Link
e.g. geometrically distinct e.g. Controlling the
e.g. Process linking
part holder
number of screwing prevents human errors
operations
© WZL / IPT
e.g. Andon-chord
to halt production
line
e.g. Pick-to-Light
e.g. quality circel,
for rack unloading control Mutual examination
of the group
page 18
Notes on figure:
Poka Yoke (jap. avoiding unintentional mistakes) stands for the usage of fail safe equipment in
the production process. Poka Yokes are supposed to protect the machine operator from human
errors in an easy way. Special attention is paid to the workers participation and to their errors in
the production process. The aim is to avoid product defects caused by human errors such as
inattention, stress or misinterpreting, due to cumbering working environment or poor working
conditions. An example is part scanning, which ensures the correct placing of the part in the
machine by analysing its shape.
In Poka Yoke systems the basis elements of initializing and triggering mechanisms are
differentiated from the regulation mechanism. Another important element is team work (quality
circle). On one side it improves Poka Yoke systems, on the other side teamwork is being
improved by Poka Yoke.
To prevent error repeating, error source inspections are made in combination with Poka Yoke. By
using this two principles errors can be suppressed efficiently and effectively.
L9 page 14
lecture 9
7) The 7 types of wasting (Muda) in Lean Production

Equipping
Screwing together
Welding
Pressing
Varnishing
Activities that add value
Value adding
work
Wasting that can be
eliminated straight away
katakana muda
Worker
movements
Wasteful works that
must be done
Stacking parts
Removing packing material
Removing chippings
Encompassing part acquiring paths
Work
Non value adding work
Kanji muda

hirigana muda

Bringing back to start position
Cleaning supply areas
Holding keys and switches
Manual operation of machines
Wasting caused by the
facility or machine
Idle ways at hydraulic or pneumatic powered
tools
To long feed paths
Oversized machines
Ref. to Takeda 1999
© WZL / IPT
page 19
Notes on figure:
The figure shows the three levels of wasting in Lean Management.
The first level is katakana muda. It is easily identifiable and has to be eliminated straight away.
The second level is hiragana muda. It contains the largest part of non value adding work.
The third level of wasting is kanji muda. It represents the type of wasting made for example by a
by output oversized facility that is used at full power regardless of cycle time. Other examples
include long feed paths to the part and a worker spectating to such operations.
There are 7 Muda in total:
– Muda trough overproduction
– Muda trough waiting times
– Muda trough transport
– Muda at the machining
– Muda trough stock keeping
– Muda trough unnecessary movements
– Muda trough the production of bad parts
L9 page 15
lecture 9
8) Visual management as a control and leading instrument
Factory
informations
Advice and
warning signs
Achievement
of objectives
Product and
storage location tag
Standardized
worksheets
Status displays and
Andon-Board
Error prevention
displays
Area marking
Process oriented layout
Ref to. Monden 1994 and Ohno 1993
© WZL / IPT
page 20
Notes on figure:
Visual management is the communication basis of the Lean Production system and thus a key
component. Three important aspects of visual management can be distinguished:
– Communication of information: direct or indirect sharing of your work data with co-workers
to stimulate their intellectual contribution
– Communication of work standards and procedures: explicit knowledge documentation of
work relevant data
– Visual configuration of workplaces and processes: creating an overview which allows the
recognition of any deviation from the OUGHT TO state. This implies the setting of OUGHT
TO states
Within the Toyota Production System the 6S-rules are the basic fundament for visual
management (see L9 page 20).
L9 page 16
Lecture 9
Contents
Systems und methods of Lean Production
Conversion to the Lean Production principle
© WZL / IPT
page 21
Notes on figure:
L9 page 17
Lecture 9
Value stream design: The current tool in Lean Production
Select
product family
Structure of
methodology
ABC GmbH
Design of the
actual state
Design of the
target state
conversion
Group of products at
the end of the value
stream
Rough outline of
material and
information flow
Draw the attainable,
future value stream in
twelve months
Provide a plan of value
stream (year shedule)
Basis: Similar
processing steps and
machines equipment
Analysis and comprehensive of the current
function of the factory
Basis: Basic rules of
Lean Production
Systems
Continuous adjustment
and examination of the
desired value stream
Customer or
supplier (external)
Production
planning
Gradual conversion
Electrical
information flow
MRP
Tuesday
+ Friday
Truck
supply
Fa. Cologne
Information flow
Pressing
I
assembly
4 x / day
I
Stock
(quantity and
current value notes)
Ref to. Rother 2000/ Erlach 2003
I
2 shifts
Circle time
Retool time
delay (%)
Material „PUSH“
(push forwarded)
2 shifts
Circle time
Retool time
delay (%)
Process case
Data case
© WZL / IPT
page 22
Notes on figure:
Value stream means all activities (as well as added value and not added value), which are
necessary to bring a product from the raw material to the hands of the customer. Value stream
design represents the whole value stream to improve it afterwards. Thus it designates a method
for the improvement or organisation of the process steps. Material as well as information flows
and temporal coupling of the production steps are regarded together, in order to achieve a
comprehensive optimisation.
The procedure in the value stream design can be summarized in the following way:
Directly in the production the value stream is noted with simple pictures and symbols. The
symbols are arranged that everyone understands the value stream without individual training. The
analysis of value stream always begins with the supplier and ends at the costumer of the current
production process for one division. After the admission of the actual condition the elaboration of
an improved specified condition follows. The methods offers some fundamental suggestions to
improve the value stream. Suggestions are the avoidance of material stocks by introducing the
continuous flow production or by introducing the decentralized control structures.
L9 page 18
Lecture 9
Example: Process optimisation with the value stream principle
Before
After
Production
controlling
supplier
costumer
Production
controlling
Sc
hri
ttm
ac h
supplier
forwarding
costumer
er
forwarding
B, C & D
B
A
D
A
C
90s
6d

30s
180s
5,4d
2d
All processes are central planned
Push-controlling
Processes are secured by stocks
Turn-around time: 300 seconds + 14,8 days
© WZL / IPT
90s
1,4d
3d

190s
1d
1d
The pacemaker controls all processes
Supermarket und Kanban-controllling
Capacity leveling in the working group
Turn-around time: 280 seconds + 5 days
page 23
Notes on figure:
L9 page 19
Lecture 9
6S – Order & Cleanlineless: Problems, nobody see, do not disturb
Step 1 of the conversation
Seiri:
Separation of required and not required units. Units
which are not in use, have to remove immediately.
Seito: The necessary units have to stand on comprehensively
defined places. Everyone must have a good access.
Seiso: Thorough cleaning
What‘s
wrong with
this?
Step 2 of the conversion
Seiketsu:
Keep the condition created before
Step 3 of the conversion
Shitsuke:
Shukan:
Accomplish the work in the correct way
Internalise the learned and standardised
Ref. to Takeda 1999
© WZL / IPT
page 24
Notes on figure:
„6S“ comes from the Japanese and stand for Seiri (clearance), Seiton (arrange), Seiso
(cleanlineless), Seiketzu (tidiness), Shitsuke (discipline) and Shukan (adaption). It describes the
tidiness and cleanlineless at the working place and in the whole enterprise. However “6S” is more
than keep the working place clean; it is an attitude of mind, which affects very positively the
quality of the staff members and of the products. The 6S is a basis for the introduction of a
synchronous production system, just like standardisation and visualisation (or visual
management), which are linked closely with the topic 6S.
Exemplary statements supporting the implementation of of 6S:
– As long as the ways are dirty, improvement is still needed
– With dirty clothes you produce bad products
– It is important to copy good things
L9 page 20
Lecture 9
Example:
Optimized sidewalks & utilization of capacity in U-layout
Example 1:
3 Capacity steps of an manual assembly
1 coworker
7
6
Example 2:
Operation of several machines in the
manufacturing
5
4
2 coworker
1
2
3
7
6
5
4
3 coworker
1
2
3
7
6
5
4
1
2
3
© WZL / IPT
page 25
Notes on figure:
In manufacturing area, by arranging machines in product-oriented layout (instead of a functionoriented arrangement), the flow-principle can be supported (example 2).
The U-Layout gives the following advantages:
– Multi-machine operation in coherence with short routes.
– High communication and, thus, simplification of the mistake-search and adjustment
– Consolidated area usage
– Scalability (e.g. in case of fluctuant volume)
L9 page 21
Lecture 9
Example of optimization of setup time (SMED-principle by Toyota):
Separation from “internal” and “external” activities
A
Activity consisting of individual components
Tcritical
B
Identification of activities,
which can be realised preliminary
Tcritical
C
Reorganisation of the activities
Tcritical
Coverage
Setup procedure
Machine maintenance
Adjustment procedure
...
Proceeding
Group of few people revises the
expiration of an activity according
to the steps A-D.
Survey of the result.
Adaptation or extension of existing
standards
caption:
Tcritical
D
Optimization of the remaining activities
Tcritical
© WZL / IPT
Required period for the principle
activity
Activity, which is realised during the
critical time
Activity, which is preliminary
implemented
page 26
Notes on figure:
The term SMED is an abbreviation for “Single Minute Exchange of Die“. This represents a method
to minimized system stops which are caused by setting up procedures. The method and term
SMED derives from the Toyota Production System. There the downtime presents a successcritical factor as a result of tool changes in the context of the Just in Time manufacturing of small
lot sizes.
The method can always be used, where time-critical, standardised activities (e.g. at intensive
investment plants) must be accomplished (e.g. retooling procedures, maintenance work or material
assembly.
L9 page 22
Lecture 9
Example: KVP - workshops in the production
KVP - Workshops in production are
accomplished as group activity and as
comprehensive functions.
e.g. long sidewalks in a work station
of a machine assembly
The expiration is oriented at the PDCA cycle
1.
Admission of the actual state in production
2.
Systematically search for weak points: The
7 kinds of waste
3.
Creative identification of improvement
measures
4.
Conversion still in the Workshop
5.
Documentation and monitoring of the new
standard, pursuit of long-term measures
Measures, e.g.:
Improvement of the material supply
“golden-zone”
Reorganisation of work contents
Change of the work contents “1 touch”-assembly
© WZL / IPT
page 27
Notes on figure:
L9 page 23
Lecture 9
Continuous improvement (Kaizen):
Example from the Ford Production System
e
nc
na
te
Au
to
m
ob
ile
s
m
6S
ai
nt
en
an
ce
KVP
4 principles of visual
Warehouse control
n
ai
Ab
br
ev
ia
tio
m
n
of
se
tu
p
d
ne
an
Pl
Standard
work instructions
trix
ma
e
ng
n
ini
io tim
ct n
Tra
du ow
re e d
th
of
Warehouse reduction & KANBAN
tim
e
Productin planning and control
traceability &
Control of lot size
Source: Ford
© WZL / IPT
page 28
Notes on figure:
A substantial aspect of the concentration of added value in the Lean Production is the continuous
improvement process (jap: Kaizen). The main objective of Kaizen is the elimination of the “7 kinds
of waste”.
Kaizen is not only a high management instrument; in fact Kaizen motivates workers to revise all
processes critically. With help of Kaizen, companies engage their employees to have an acute
eye on all unproductive, not value creating processes – This is done by Kaizen workshops,
circles or Kaizen suggestion systems. Target is the fast, unbureaucratic detection of easily
transformable activities.
L9 page 24
Lecture 9
Lean Production: a challenge for the culture in the enterprise
Lean – Thinking
Lean - Behaviour
Flexibility is more important than
efficiency (Scale)
Decisions are made as a result of
long-term, systematic considerations
Added value results from the
production staff member, indirect
spheres are service provider
The management is closely
connected to the reality of everyday
life in the production, the “Gemba”
Everyone should understand, how its
work contributes to the company
targets
The production coworkers are really
involved in improvement activities
The causes of problems must be
addressed, not only the symptoms
A problem is a chance for
improvement
Manager work to solve system
problems
There is an open dialogue of the
colleagues between all levels.
source: John Drew: Journey to Lean, 2004
© WZL / IPT
page 29
Notes on figure:
L9 page 25
Lecture 9
Production Systems in different enterprises
Taktfertigung
Fließfertigung
Pull production
Remove of waste
Kontinuierliche
Continuous
improvement
Verbesserung
Just in Time
Production smoothing
Costumer orientation
(internal & external)
Visual management/ 5A
Fast identification of problems
and error correction
Stable processes/products and
Preventive quality management
Quality
Qualitätas
im
Mittelpunkt
focus
Standardi
Standar sierung
dization
Standardized methods
and processes
Job safty and
Environmental awareness
Structure in working grpoups
Participation and development
of colleagues
Leading
Clear tasks and roles
Arbeitsstrukturen
Work structures and
und
Gruppenarbeit
teamworkt
92 detailed
Vertiefende
MPSMPS
methods
--Methoden
undund
tools
-Werkzeuge
KVP
Assembly and
manufacturing places
Visualisation and
Standardization
colleagues
Labour organisation
and
personal management
Zero-defects concpts
Hire principle
(bonus wages)
Total Productive
Maintenance- TPM
Material supply
Just-In-Time
Order and cleanlineless (5-S)
© WZL / IPT
page 30
Notes on figure:
Methods, instructions, methodologies, work standards but also company-cultural aspects are
structured in a frame: the Production System. The Toyota Production System (TPS) is meant to
be exemplary to the automobile industry.
Today, nearly every company has got its own production systems, adapted to the individual
organization, culture and company structure.
The Mercedes-Benz Production System (see figure upper right) consists of 3 levels. 5 basic
elements form the “roof”, which is carried by 15 production principles. The fundament for
implementing these principles is supported by altogether 92 methods, tools and rules.
L9 page 26
Lecture 9
List of litarture
Askin an Goldebrg: Design and Analysis of Lean Production Systems. J. Wiley, New York 2002
Drew, J.: Journey to Lean, Making operational change stick, Großbritannien, 2004
Erlach, K.: Mit Wertstromdesign zur schnellen Fabrik, Stuttgart 2003
Görgens, J.: Just-in-Time Fertigung: Konzept und modellgestützte Analyse. Schäffer-Poeschel
Verlag, Stuttgart 1994
Imai, M.: Kaizen: Der Schlüssel zum Erfolg der Japaner im Wettbewerb. 7. Auflage,
Wirtschaftsverlag Langen Müller/Herbig, München 1992
Jansen, H.H.: Lean Production in der mittelständischen Industrie. Springer Verlag, Berlin 1993
Mehdorn, H., Töpfer, A.: Besser-Schneller-Schlanker: TQM-Konzepte in der
Unternehmenspraxis. Hermann Luchterhand Verlag, Neuwied, Kriftel, Berlin 1994
Mondon, Y.: Toyota Production System – An Integrated Approach in Just-in-Time, London 1993
N.N.: Lean Management. Der Weg zur schlanken Fabrik. gfmt, St. Gallen 1993
N.N.: Lean Production. Tragweite und Grenzen eines Modells. Fachtagung, RKW, Eschborn
1992
Ohno, T.: Das Toyota-Produktionssystem. Übersetzung von W. Hof. Campus Verlag, Frankfurt
1993
Pfeiffer, W.: Lean-Management: Grundlagen der Führung und Organisation lernender
Unternehmen. Erich Schmidt Verlag,Berlin 1994
Reingold, E.M.: Toyota. People, Ideas and the Challenge of the New. Japanese Business,
Peguin Books, London 1999
Rother, M.: Learning to See, Brookline, Massachusetts: Lean Enterprise Institute, 2003
Sekine, K.: Produzieren ohne Verschwendung. Der japanische Weg zur schlanken Produktion.
Japan Service, Verlag Moderne Industrie. LandsbergLech 1994
Stürzl, W.: Lean Production in der Praxis: Spitzenleistung durch Gruppenarbeit. Junfermann
Verlag, Paderborn 1993
Takeda, H.: Das synchrone Produktionssystem. Just-in-Time für das ganze Unternehmen,
verlage moderne industrie Landsberg, 1999
Tapping, D.: Value Stream Mamagement for the Lean Office, New York 2002
Wildemann, H.: Lean Management: Strategien zur Erreichung wettbewerbsfähiger Unternehmen.
FAZ Verlagsbereich Wirtschaftsbücher, Frankfurt a. Main 1993
Womack und Jones; The machine that changed the world, Rawson Associates, New York 1990
Womack und Jones; Lean Thinking, New York 1996
L9 page 27