1. Simulation Supplement B
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2. Simulation Process
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3. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

4. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Average weekly production requirements =
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

5. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Average weekly production requirements = 200(0.05)
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

6. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Average weekly production requirements = 200(0.05) + 250(0.06)
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

7. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Average weekly production requirements = 200(0.05) + 250(0.06) + 300(0.17) + … + 600(0.02) = 400 hours
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

8. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Average weekly production requirements = 400 hours
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

9. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

10. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours =
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

11. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 320(0.30)
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

12. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 320(0.30) + 360(0.40) +
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

13. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 320(0.30) + 360(0.40) + 400(0.30)
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

14. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 320(0.30) + 360(0.40) + 400(0.30) = 360 hours
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

15. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 360 hours
Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

16. Simulation Process Weekly Production Relative
Requirements (hr) Frequency
Total 1.00
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Example B.1
Average weekly production requirements = 400 hours
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

17. Simulation Process Event Weekly Regular Relative
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly
Demand (hr) Probability
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

18. Simulation Process Event Weekly Regular Relative
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly
Demand (hr) Probability
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

19. Simulation Process Event Weekly Random Weekly Random Regular Relative
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

20. Simulation Process Event Weekly Random Weekly Random Regular Relative
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
–04
–10
–27
–32
–62
–77
–83
–97
–99
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

21. Simulation Process Event Weekly Random Weekly Random Regular Relative
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
– –29
– –69
– –99
–32
–62
–77
–83
–97
–99
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

22. Simulation Process Simulation Process 1. Draw a random number.
2. Find the random number interval for production.
3. Record the production hours.
4. Draw another random number.
5. Find the random number interval for capacity.
6. Record the capacity hours.
7. If CAP ≥ PROD, then IDLE HR = CAP – PROD.
8. If CAP < PROD, then SHORT = PROD – CAP.
If SHORT ≤ 100, then OVERTIME HR = SHORT
and SUBCONTRACT HR = 0.
If SHORT > 100, then OVERTIME HR = 100
and SUBCONTRACT HR = SHORT – 100.
9. Repeat steps 1–8 to simulate 20 weeks.
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
– –29
– –69
– –99
–32
–62
–77
–83
–97
–99
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Average weekly production requirements = 400 hours
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

23. Simulation Process Simulation Process 1. Draw a random number.
2. Find the random number interval for production.
3. Record the production hours.
4. Draw another random number.
5. Find the random number interval for capacity.
6. Record the capacity hours.
7. If CAP ≥ PROD, then IDLE HR = CAP – PROD.
8. If CAP < PROD, then SHORT = PROD – CAP.
If SHORT ≤ 100, then OVERTIME HR = SHORT
and SUBCONTRACT HR = 0.
If SHORT > 100, then OVERTIME HR = 100
and SUBCONTRACT HR = SHORT – 100.
9. Repeat steps 1–8 to simulate 20 weeks.
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
– –29
– –69
– –99
–32
–62
–77
–83
–97
–99
10 Machines
Existing
Demand Weekly Capacity Weekly Sub-
Random Production Random Capacity Idle Overtime contract
Week Number (hr) Number (hr) Hours Hours Hours
TABLE B.2 20-WEEK SIMULATIONS OF ALTERNATIVES
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Total
Weekly average
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

24. Simulation Process Simulation Process 1. Draw a random number.
2. Find the random number interval for production.
3. Record the production hours.
4. Draw another random number.
5. Find the random number interval for capacity.
6. Record the capacity hours.
7. If CAP ≥ PROD, then IDLE HR = CAP – PROD.
8. If CAP < PROD, then SHORT = PROD – CAP.
If SHORT ≤ 100, then OVERTIME HR = SHORT
and SUBCONTRACT HR = 0.
If SHORT > 100, then OVERTIME HR = 100
and SUBCONTRACT HR = SHORT – 100.
9. Repeat steps 1–8 to simulate 20 weeks.
TABLE B.1 RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS
Event
Weekly Random Weekly Random
Demand (hr) Probability Numbers Capacity (hr) Probability Numbers
– –29
– –69
– –99
–32
–62
–77
–83
–97
–99
10 Machines
Existing
Demand Weekly Capacity Weekly Sub-
Random Production Random Capacity Idle Overtime contract
Week Number (hr) Number (hr) Hours Hours Hours
TABLE B.2 20-WEEK SIMULATIONS OF ALTERNATIVES
Regular Relative
Capacity (hr) Frequency
320 (8 machines) 0.30
360 (9 machines) 0.40
400 (10 machines) 0.30
Average weekly operating machine hours = 360 hours
360 (9 machines) 0.30
400 (10 machines) 0.40
440 (11 machines) 0.30
Total
Weekly average
Comparison of 1000-week Simulations
10 Machines 11 Machines
Idle hours
Overtime hours
Subcontract hours
Cost $1, $1,159.50
TABLE B.2 COMPARISON OF 1,000 WEEK SIMULATIONS
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25. Random Numbers Figure B.1
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26. Best Car Simulation Model
Example B.3
Figure B.2
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.

27. Inventory Simulation Model
Figure B.3
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved.