2. METODE SIMULASI Pertemuan 20
Matakuliah : J Analisis Kuantitatif Bisnis
Tahun : 2009/2010
METODE SIMULASI Pertemuan 20

3. Framework Simulasi Monte Carlo Simulasi dan Persediaan
Simulasi dan Masalah Antrian
Aplikasi Model Simulasi
Pengambilan Keputusan Berdasarkan Model Simulasi
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4. Batasan Simulasi Monte Carlo
Apabila suatu persoalan sudah dapat diselesaikan atau dihitung jawabannya secara matematis dengan tuntas, maka hendaknya jangan menggunakan simulasi ini
Apabila sebagaian persoalan tersebut dapat diselesaikan secara analitis dengan baik, maka penyelesaiannya lebih baik dilakukan secara terpisah. Sebagian secara analitis dan sebagian lagi simulasi
Apabila mungkin dapat digunakan simulasi perbandingan
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5. Contoh Soal
Harry’s Auto Tire sells all type of tires, but a apopular radial tire accounts for a large portion of Harrycost ’s overall sales. Recognizig that inventory costs can be quite siginificant with this product, Harry’s wishes to determine a policy for managing this inventory. To see what the demmand would like over a period of time, he wishes to simulate the daily demand for a number of days.
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6. Step – 1 Establishing Probability Distributions
To establish a probabilty distribution for tires we assume that historical demand is a good indicator of future outcomes
Often, managerial estimates based on judgment and experience are used to create a distribution.
The distribution themselves can be either emperical or based on the commonly known normal, binomial, poisson or exponential patterns
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7. Step – 2 Building a Cummulative Probability Distribution for Each Variable
Histrical Daily Demand for Radial Tires at
Harry’s Auto Tire
Demand for Tires
Frequensy (days) 10 1 20 2 40 3 60 4 5 30
Total
200
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8. Probability Demand Demand for Tires Frequensy (days) 10 /200 = 0.05 1
10 /200 = 0.05 1
20 / 200 = 0.10 2
40 / 200 = 0.20 3
60 / 200 = 0.30 4 5
30 / 200 = 0.15
Total
200
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9. Step – 3 Setting Random Number Intervals
Cummulative Probabilties for Radial Tires
Daily Demand
Probabality
Cummulative Probability
0.05 1
0.10
0.15 2
0.20
0.35 3
0.30
0.65 4
0.85 5
1.00
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10. Step – 4 Generating Random Numbers
Daily Demand
Probability
Cummulative Probabilty
Internal of Reandom Numbers
0.05
01 to 05 1
0.10
0.15
06 to 15 2
0.20
0.35
16 to 35 3
0.30
0.65
36 to 65 4
0.85
66 to 85 5
1.00
86 to 00
Assignment of random number interval for Harry’s Auto Tire
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11. Step – 5 Simulating the Experiment
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12. Simulated Daily Demand
Day
Random Number
Simulated Daily Demand 1 52 3 2 37 82 4 69 5 98 6 96 7 33 8 50 9 88 10 90
39 = total 10 day demand
3.9 average daily demand
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13. Expected Daily Demand Σ Expected Daily Demand =
= (Probability of i tires)x(demand of I tires)
= (0.05) (0) + (0.10) (1) + (0.20) (2) + (0.30) (3) + (0.20) (4) + (0.15) (5)
= 2.95 Tires 5 Σ
i = 0
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