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STOPWATCH TIME STUDY!ANALISA DAN PENGUKURAN KERJA
Debrina Puspita Andrianie"Mail':'[email protected]'
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'
www.debrina.lecture.ub.ac.id)2) 12/11/14)
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.'
www.debrina.lecture.ub.ac.id)3)12/11/14)
• 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
www.debrina.lecture.ub.ac.id)8)12/11/14)
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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