standard data system! - Debrina`s Blog as Industrial Engineer
Transcription
standard data system! - Debrina`s Blog as Industrial Engineer
STANDARD DATA SYSTEM! ANALISA DAN PENGUKURAN KERJA Debrina Puspita Andriani e"Mail':'[email protected]' Blog':'http://debrina.lecture.ub.ac.id' 12 METODE PENGUKURAN [WAKTU] KERJA PENGUKURAN)[WAKTU]) KERJA) DIRECT' INDIRECT' STOPWATCH' STANDARD' DATA' WORK' SAMPLING' PMTS) Regression' Analysis' 2) 26/11/14) www.debrina.lecture.ub.ac.id) Standard Data Systems A'standard'data'system'(SDS)'in' work'measurement'is'a'database' of'normal'time'values,'usually' organized'by'work'elements'that' can'be'used'to'establish'time' standards'for'tasks'composed'of' work'elements'similar'to'those'in' the'database.'' ' Standard'data'is'a'catalog'(list)'of' elemental'time'standards' developed'from'a'database' collected'over'years'of'motion'and' time'study.' 3) 26/11/14) www.debrina.lecture.ub.ac.id) Standard Data System Defined ! The'normal'time'values'for'the'work'elements'are'usually'compiled'from' previous'direct'time'studies'(DTS).'' ! Using'a'standard'data'system,'time'standards'can'be'established'before' the'job'is'running.' ! When'a'predetermined'motion'time'system'is'used'to'develop'times'for' a'standard'data'system,'it'is'for'either'of'the'following'purposes:''' ! to'supplement'the'database'of'direct'time'study'values'because'some' of'those'data'are'missing,'or'' ! to'develop'the'SDS'database'of'work'element'normal'times'from'the' basic'motion'element'times'in'the'PMTS.'' 26/11/14) 4) www.debrina.lecture.ub.ac.id) PMTS and SDS Compared 26/11/14) 5) www.debrina.lecture.ub.ac.id) Why do we need Standard Data? Reduce)time)required)to) develop)time)standards)(as) compared)to)time)study).'' Reduce)cost)of)developing) time)standards)(due) primarily)from)reduced) time)required)to)develop) the)standards).'' Permit)the)establishment) of)accurate)time)standards) before)the)job)is) performed.' Time)standards)from) standard)data)are)more) consistent.' Standard)data)time) standards)are)more) accurate.' Simplifies)issues) associated)with)unions.'' Could)be)used)as)a)check) for)time)study.' 26/11/14) 6) www.debrina.lecture.ub.ac.id) Similarity)in)tasks' Batch)production' Large)number)of) standards)to)be)set' Need)to)set)standards) before)production' 7) 26/11/14) www.debrina.lecture.ub.ac.id) When a SDS is Most Suitable ? Developing)a)SDS' ! A' standard' data' system' is' almost' always' custom"engineered' and' developed'for'the'facility'that'will'use'the'system.'' ! Because' each' plant’s' products,' production' methods,' and' policies,' including'its'policy'on'time'standards,'tend'to'be'unique'!' a' standard' data' system' developed' for' one' company' cannot' be' readily'migrated'to'another'company.'' ! The' general' steps' in' an' SDS' development' project' are' outlined' in' Table'15.2.' 26/11/14) 8) www.debrina.lecture.ub.ac.id) 26/11/14) 9) www.debrina.lecture.ub.ac.id) Classification of Work Elements • The'database'in'a'standard'data'system'is'organized'by'work' elements.'' • The'classification'of'work'elements'in'a'standard'data'system' must'account'for'differences'between'the'following'element' types:' 1. Setup'versus'production'elements' 2. Constant'versus'variable'elements' 3. Worker"paced'versus'machine'elements' 4. Regular'versus'irregular'elements' 5. Internal'versus'external'elements' 26/11/14) 10) www.debrina.lecture.ub.ac.id) Setup vs. Production Elements • Setup)elements)"'associated'with'activities'required'to' change'over'from'one'batch'to'the'next' – Performed'once'per'batch' • Production)elements)"'associated'with'the'processing'of' work'units'within'a'given'batch' – Performed'once'per'work'unit' • Batch)time) ' '' ! ! ! Tb)=)Tsu)+)Q'Tc' 'where'Tb'='batch'time,'Tsu'='setup'time,'Q'='quantity,'and'Tc'='cycle'time' 26/11/14) 11) www.debrina.lecture.ub.ac.id) Constant vs. Variable Elements • Constant)elements)"'same'time'value'in'all'time'studies'and' tasks' – Replace'cutting'tool'in'tool'post' – Dial'telephone'number'of'customer' ' • Variable)elements)"'same'basic'motion'elements'but'normal' times'vary'due'to'differences'in'work'units' – Load'work'piece'into'machine' – Keypunch'address' 26/11/14) 12) www.debrina.lecture.ub.ac.id) Operator-Paced vs. Machine Elements • Operator`paced)elements)"'manual'elements' – Can'be'setup'or'production'cycle'elements' – Can'be'constant'or'variable' • Machine`controlled)elements'"'machine'time'depends'on' machine'operating'parameters' – Once'parameters'are'set,'the'machine'time'can'be'determined'with' great'accuracy' – Characterized'by'little'or'no'random'variations' 26/11/14) 13) www.debrina.lecture.ub.ac.id) Other Work Element Differences • Regular)elements)"'performed'once'every'cycle' • Irregular)elements)"'performed'less'frequently'than'once'per' cycle' – Must'be'prorated'in'regular'cycle' • External)elements)"'manual'elements'performed'in'series' with'machine'elements' • Internal)elements)"'manual'elements'performed'at'same' time'machine'is'running' 26/11/14) 14) www.debrina.lecture.ub.ac.id) than'dividing'the'task'into'work'elements'and' determining'element'normal)times) ! When'appropriate:' ! Work'elements'of'task'are'highly'variable' ! Elements'are'difficult'to'separate'or'identify' ! Task'consists'of'many'elements' ! Many'elements'are'similar' ! Time'standard'will'not'be'used'for'wage'incentive' purposes' 26/11/14) 15) Work Cycle Standard Data ! A'SDS'that'uses'normal'times'for'the'entire'task'rather' www.debrina.lecture.ub.ac.id) 1. Checkout'of'customers'at'supermarket'counter' ! Simpler'to'determine'time'per'customer'than'to'break'the' time'into'elements' 2. Prepare'legal'document'for'client' ! Start'with'standard'document'form'(e.g.,'will)'and'edit'for' specific'needs'of'client' 3. Proofreading'a'document' ! Time'estimate'based'on'the'number'of'pages'to'proofread' 26/11/14) 16) Work Cycle Standard Data ! Examples:' www.debrina.lecture.ub.ac.id) Machine-Controlled Elements • Examples:' – Power'feed'motion'of'a'machine'tool' • Once'activated'by'worker,'machine'time'depends'on'feed'and' speed'settings'and'dimensions'of'work'piece' – Semiautomatic'cycle'of'a'machine' • Machine'cycle'operates'under'computer'numerical'control' (CNC)' – Fully'automated'cycle' • Operator'periodically'attends'machine' 26/11/14) 17) www.debrina.lecture.ub.ac.id) Machine Times for Machining • Machining'"'family'of'processes'in'which'excess'material' is'removed'from'a'starting'work'piece'by'a'sharp'cutting' tool'so'the'remaining'part'has'the'desired'geometry' – Common'machining'operations:' • Turning' • Drilling' • Milling' • Machining'times'can'be'calculated'or'measured'with' great'accuracy,'given'the'machine'settings'(feeds'and' 26/11/14) speeds)'and'part'dimensions' 18) www.debrina.lecture.ub.ac.id) Turning Operation 26/11/14) 19) www.debrina.lecture.ub.ac.id) Drilling Operation: Through Hole 26/11/14) 20) www.debrina.lecture.ub.ac.id) Milling Operation: Peripheral Milling 26/11/14) 21) www.debrina.lecture.ub.ac.id) Peripheral Milling: Approach Distance 26/11/14) 22) www.debrina.lecture.ub.ac.id) Milling Operation: Face Milling 26/11/14) 23) www.debrina.lecture.ub.ac.id) Face Milling: Approach and Over Travel 26/11/14) 24) www.debrina.lecture.ub.ac.id) Calculation of Machining Times • Basic'approach'to'calculate'machining'times:' – Determine)the)length)of)the)cut) ' ' 'L)=)mm)or)inch) • Add'allowances'for'approach'and'over'travel'if'applicable' – Divide)by)feed)rate,'which'is'the'travel'speed'of'the'cutting'tool'in' the'direction'of'the'length' ' ' 'fr'=)mm/min)or)inch/min) • Thus,'machining)time)) ' 26/11/14) ' ' 'Tm)=)L/fr' 25) www.debrina.lecture.ub.ac.id) (a)) 26/11/14) 26) www.debrina.lecture.ub.ac.id) 26/11/14) 27) www.debrina.lecture.ub.ac.id) www.debrina.lecture.ub.ac .id) 26/11/14) Let’s Try!' Example 26/11/14) 29) www.debrina.lecture.ub.ac.id) Example • Bila'speed'(v)'='240'm/menit;'maka'putaran'spindle'dapat' dihitung'dengan'formulasi':' '' v ×1000 240 ×1000 N= = = 1530rpm ' τ ×D τ × 50 • Bilamana'mesin'bubut'diatas'memiiki'maximum!spindle!speed! 1.000'rpm;'maka'putaran'(n)'='1.000'rpm'bisa'diaplikasikan' untuk'pengerjaan'pembubutan'dan'waktu'pemotongan'dapat' dihitung'dengan'formulasi'sebagai'berikut'':' ' L×i 256 ×1 t = = = 0,67 menit ' s × n 1000 × 0,38 '(i!='frekuensi'pemotongan)' ' • Ketidak'telitian'dari'problematika'diatas'bisa'di'sebabkan' oleh':' '(a)'Bekurangnya'putaran'spindle'(kecepatan'spindle)'selama' pemotongan'berlangsung'(bisa'di'check'dengan'“tachometer”)' '(b)'Variasi'dari'jarak'pahat'ke'benda'kerja'saat'pemotongan' (distance!approach)' 26/11/14) 30) www.debrina.lecture.ub.ac.id) 26/11/14) 31) www.debrina.lecture.ub.ac.id) 26/11/14) 32) www.debrina.lecture.ub.ac.id) ! Associated'costs'savings' 2. Capability)to)set)standards)before)production) 3. Avoids)need)for)performance)rating) ! Controversial'step'in'direct'time'study' 4. Consistency)in)the)standards) ! Based'on'averaging'of'much'DTS'data' 5. Inputs)to)other)information)systems) SDS Advantages 1. Increased)productivity)in)setting)standards) ! Product'cost'estimating,'computer"assisted' process'planning,'MRP' 26/11/14) 33) www.debrina.lecture.ub.ac.id) ! Developing'a'SDS'requires'considerable'time' and'cost' 2. Source)of)data) ! Large'file'of'previous'DTS'data'must'exist' 3. Methods)descriptions) ! Documentation'still'required' 4. Risk)of)improper)applications)) SDS Limitations 1. High)investment)cost) ! Attempting'to'set'standard'for'tasks'not' covered'by'SDS' 26/11/14) 34) www.debrina.lecture.ub.ac.id) “Knowing exactly what you want to do, and then seeing that they do it the best and cheapest way.” F-ede-ick W. Ta.lo- 26/11/14) 35) www.debrina.lecture.ub.ac.id)