STOPWATCH TIME STUDY!ANALISA DAN PENGUKURAN KERJA

Debrina Puspita Andrianie"Mail':'debrina@ub.ac.id'

Blog':'http://debrina.lecture.ub.ac.id/'

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METODE PENGUKURAN [WAKTU] KERJA

PENGUKURAN)[WAKTU])KERJA)

DIRECT' INDIRECT'

STOPWATCH'

WORK'SAMPLING'

STANDARD'DATA'

PMTS)

Regression'Analysis'

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DIRECT VS INDIRECT TIME STUDY

DIRECT)TIME)STUDY)!  Kelebihan':'

!  PRAKTIS,'karena'hanya'mencatat'waktu'saja'tanpa'menganalisa'gerakan"gerakan'kerja.'

!  Biaya'lebih'murah'(pada'awalnya).'

!  Kekurangan):)!  Dibutuhkan'waktu'

pengamatan'yang'lebih'lama'agar'data'AKURAT'&'TELITI.'

!  Biaya'lebih'MAHAL'karena'harus'datang'langsung'ke'lokasi'pengamatan'(pada'akhirnya).'

INDIRECT)TIME)STUDY)!  Kelebihan):)

!  Waktu'pengamatan'relatif'SINGKAT'karena'cukup'merekam'aktivitas'kerja.'

!  Biaya'relatif'lebih'MURAH'karena'tidak'perlu'berulang'kali'datang'ke'lokasi'pengamatan.'

!  Jumlah'pengukuran'tidak'harus'sebanyak'penghukuran'langsung'

!  Kekurangan):)!  Terkadang'tabel'gerakan'kerja'orang'

EROPA'tidak'cocok'dengan'INDONESIA.'

!  Dibutuhkan'KETELITIAN'yang'tinggi'dalam'membreakdown'gerakan"gerakan'kerja.'

!  Data'waktu'gerakan'kerja'harus'disesuaikan'dengan'JENIS'PEKERJAAN.'

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•  Element'is'a'component'of'job'or'task'that'are'logical'divisions'with'easily'identifiable'starting'and'end'points,'and'are'repeated'on'a'regular'basis.'

•  Cycle'is'the'completion'of'the'activities'(elements)'required'to'perform'the'job'under'study.''

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Types)of)elements)

A'repetitive'element''is'an'element'which'occurs'in'every'

work'cycle'of'the'job.''

An'occasional'element'does'not'occur'in'each'work'cycle'of'the'job,'but'which'may'occur'at'regular'or'irregular'intervals.'e.g.'

machine'setting.'

For'a'constant'element'the'basic'time'remains'constant'whenever'it'is'performed.'e.g.'

switch'the'machine'on.'

A'variable'element''is'an'element'for'which'the'basic'time'varies'in'relation'to'some'characteristics'of'the'product,'equipment'or'process,'e.g.'

dimensions,'weight,'quality'etc.'e.g.'push'trolley'of'parts'to'next'

shop.'

A)manual)element)is'an'element'performed'by'a'

worker.'

A)machine)element)'is'automatically'performed'by'a'

power"driven'machine'(or'process).'

A)governing)element)'occupies'a'longer'time'than'any'of'the'other'elements'which'are'being'performed'concurrently.'e.g.'boil'kettle'of'water,'while'setting'out'teapot'and'cups.'

A)foreign)element))is'observed'during'a'study'which,'after'analysis,'is'not'found'to'be'necessary'part'of'the'job.'e.g.'

degreasing'a'part'that'has'still'to'be'machined'further.'

www.debrina.lecture.ub.ac.id)6)12/11/14)

Direct Time Study

Stopwatch T-­me Study :! Elemen&kerja&berlangsung&dalam&waktu&SINGKAT&

! Waktu&siklus&kerja&PENDEK&

! Siklus&kerja&terjadi&BERULANGAULANG&! Waktu&elemen&kerja&diukur&dengan&STOPWATCH)

Wor. Sampl-­ng :! Elemen&kerja&berlangsung&dalam&waktu&LAMA&

! Waktu&siklus&kerja&PANJANG&

! Siklus&kerja&TIDAK&BERULANG&! Mencari&%&kerja&dan&%&delay&(PROBABILITAS)&

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LANGKAH – LANGKAH !PENGUKURAN [WAKTU] KERJA

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1. Mengumpulkan informasi dan peralatan

! Tentukan&TUJUAN&dari&pengukuran&kerja!&

! Melakukan&pengamatan&pendahuluan&

&(layout,&lingkungan&kerja,&mesin&yang&&

&digunakan,&dll).&

! Menyiapkan&peralatan&:&

!  stopwatch,&papan,&kalkulator,&form&pengukuran&kerja&

! Memilih&operator&yang&akan&diamaR&dan&

mengkomunikasikan&dengan&supervisor&(operator&harus&

memiliki&kemampuan&NORMAL,&bisa&BEKERJA&SAMA,&dan&

WAJAR).)www.debrina.lecture.ub.ac.id)9)12/11/14)

Stopwatch)

Electronic)Stopwatch) Mechanical)Stopwatch)

Calibrated in decimal minutes LED read-out www.debrina.lecture.ub.ac.id)10)12/11/14)

Learning Curve

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2. Membagi operasi dalam elemen-elemen

! Purpose&:&easy&to&measure&&&line&balancing&

! Separate&handling&Rme&(nonAproducRve&Rme)&with&&

operaRon&Rme&(producRve&Rme)&

! Separate&constant&element&with&variable&element.&

! Every&element&must&have&an&easily&idenRfiable&

starRng&and&ending&point&(breakpoints)&

! ConRnuiRes&between&elements&

! Elements&Rmes:&0.04min&(short),&0.25min&

(reasonable)&

! RelaRve&frequency&must&be&included&&

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3. Metode Stopwatch Time Study !  CONTINUOUS)TIMING))

!  Tombol'stopwatch'ditekan'pada'saat'awal'elemen'kerja'dan'terus'dibiarkan'berjalan'selama'periode'studi.''Pengamat'terus'melihat'jalannya'jarum'stopwatch'dan'setiap'awal/akhir'dari'sebuah'elemen'kerja'yang'ada'mencatat'dan'menuliskannya'di'lembar'pengamatan.''Waktu' setiap' elemen' kerja' akan' diperoleh' dengan' cara' “pengurangan”' dan'dilakukan' setelah' studi' pengukuran' kerja' selesai' dilaksanakan.' APA)KEKURANGANNYA?)

!  REPETITIVE)(SNAP[BACK)METHOD)))

'Jarum'penunjuk'stopwatch'selalu'dikembalikan'ke'posisi'nol'setiap'kali'satu'elemen'kegiatan'selesai'dilaksanakan.''Waktu'yang'diamati'dan'dicatat'akan'merupakan'waktu'yang'sebenarnya.''Time2 study2analyst2akan'bisa'mendeteksi'dengan'mudah'adanya'variasi'perbedaan'waktu'dari'setiap'elemen'kegiatan.'APA)KEKURANGANNYA?)

!  ACCUMULATIVE)TIMING))

'Merupakan' kombinasi' cara' pengukuran' dengan'metoda' continuous2 dan2 snap6back2(pengukuran' dilaksanakan' dengan' menggunakan' dua' atau' lebih' stopwatch' yang'bekerja'secara'bergantian).'

Continuous Method

Snapback Method

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THE RULES ! "  Don’t'comment'to'the'worker'during'

the'task'

"  Stand'(don’t'sit)'beside'the'worker'

"  Write'every'event'(even'though'it'may'seems'not'important)'

"  Have'a'good'position'to'observe'

"  Stop'the'study'if'the'worker'seems'to'be'under'pressure'and'it'affects'his/her'work'

www.debrina.lecture.ub.ac.id)15)12/11/14)

PENGAMATAN

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Performing a Time Study

Time Study Observation Sheet

Identification of operation Sandwich Assembly Date 5/17

Operator Approval Observer Smith Jones Russell

Cycles Summary 1 2 3 4 5 6 7 8 9 10 Σ t Nt RF t

Place ham, cheese, and lettuce on bread

1

2

3

4

Grasp and lay out bread slices

Spread mayonnaise on both slices

Place top on sandwich, Slice, and stack

t

t

t

t

R

R

R

R

.11 .44 .79 1.13 1.47 1.83 2.21 2.60 2.98 3.37

.04 .05 .05 .04 .06 .05 .06 .06 .07 .05 .53 .053 1.05 .056

.04 .38 .72 1.05 1.40 1.76 2.13 2.50 2.89 3.29

.07 .06 .07 .08 .08 .08 .07 .07 .10 .09 .77 .077 .077 1.00

.11 .12 .14 .12 .12 .13 .13 .13 .14 .14 1.28 1.28 1.10 .141

.93 .23 .55 1.25 1.60 1.96 2.34 2.72 3.12 3.51

.12 .10 .08 .09 .12 .10 .11 .11 .10 .10 1.03 1.03 1.10 .113

.33 .67 1.01 1.34 1.71 2.07 2.44 2.82 3.24 3.61

www.debrina.lecture.ub.ac.id)17)12/11/14)

4.  Tes Kenormalan, Tes Keseragaman,!Tes Kecukupan Data

"  TES) KENORMALAN) #) data' pengamatan' seharusnya'berjumlah'cukup'besar'(banyak)'dan'berdistribusi'normal.''

"  TES)KESERAGAMAN)#'data'harus'homogen'dan'diperoleh'dari'populasi'yang'sama.''

"  TES) KECUKUPAN)#' data' yang' dikumpulkan' telah' cukup'secara' obyektif,' dengan' konsep' statistik' (derajat' ketelitian'dan'tingkat'keyakinan/kepercayaan'yang'diinginkan).'

www.debrina.lecture.ub.ac.id)18)12/11/14)

Determining Number of Cycles

Time'measurement'•  Measuring'time'of'each'

element'•  The'number'of'

observation'of'each'element'depends'on'the)significance)level)and'required)level)of)accuracy)

'

www.debrina.lecture.ub.ac.id)19) 12/11/14)

Number of Cycles (1)

To)determine))sample)size:)

n = zs eT

2

where'

'z'=''number'of'standard'deviations'from'the'mean'in'a'normal'distribution'reflecting'a'level'of'statistical'confidence'

'T'=''average'job'cycle'time'from'the'sample'time'study''e'=''degree'of'error'from''true'mean'of''distribution'

s = = sample'standard'deviation'from''sample'time'study'

Σ(xi - x)2 n - 1

www.debrina.lecture.ub.ac.id)20)12/11/14)

Number of Cycles (2)

Example):)

• Average'cycle'time'='0.361'•  Computed'standard'deviation'='0.03'•  Company'wants'to'be'95%'confident'that'computed'time'is'within'5%'of'true'average'time'

n = = = 10.61 or 11 zs eT

2 (1.96)(0.03) (0.05)(0.361)

2

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Recom

mended)num

ber)of)cycles/observations'

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5.  Performance Rating & Waktu Normal

Normal)time):))Tn)=)Tobs'(PR))

1)'Waktu'Pengamatan'(Tobs)'

2)'TN'<'TObs'untuk'p'<'1'(100%)'

3)'TN'='TObs'untuk'p'='1'(100%)'

4)'TN'>'TObs'untuk'p'>'1'(100%)'

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WESTINGHOUSE RATING SYSTEM

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6.  Menentukan Allowance

Allowance)

Constant)

Personal)Needs) Fatigue))

Special)

Avoidable)Delays)

Unavoidable)Delays)

More)details)in):)Handbook)of)IE)(Salvendy)):)pp.)1409)www.debrina.lecture.ub.ac.id)25)12/11/14)

7.  Waktu Standar dan Output Standar

TS'=)TN'(1)+)Apfd)) OS)=)1)/)TS)

Waktu)Normal)(TN)' Allowance'

Waktu)Baku/Standard))(TS)'

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Let’s Try!'

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TUGAS 1 !  Given:'A'direct'time'study'was'taken'on'a'manual'work'

element'using'the)snapback)method.''!  The'regular'cycle'consisted'of'three'elements':'a,)b,)and)

c.' Element) d) is' an' irregular' element' performed' every'five'cycles.''

'''

''!  Determine''

'(a)'normal'time'''(b)'standard'time'for'the'cycle'using)Apfd'='0.15'

Work)element) a) b) c) d)

Observed'time'(min)' 0.56' 0.25' 0.50' 1.10'

Performance'rating' 100%' 80%' 110%' 100%'

www.debrina.lecture.ub.ac.id)28)12/11/14)

Solution (a) Normal time:

'TN 2='0.56(1.00)'+'0.25(0.80)'+'0.50(1.10)'+'1.10(1.0)/5''

' '='1.53'min'

'

(b) Standard time:

'TS'='1.53(1'+'0.15)'='1.76'min'

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“Knowing exactly what you want to do, and then seeing that they do it the best and cheapest way.”

Freder-­c. W. Taylor

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