To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Supplement B
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 Example B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (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. Simulation Process Weekly ProductionRelative Requirements (hr)Frequency Total1.00 Total1.00 RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines) (10 machines)0.30 Example B.1 Average weekly production requirements = 400 hours Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly Demand (hr)Probability
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly Demand (hr)Probability
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers – – – – – – – – –99
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers – – – – – – – – – – – –99
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Average weekly production requirements = 400 hours RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers – – – – – – – – – – – –99 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 – Repeat steps 1–8 to simulate 20 weeks.
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers – – – – – – – – – – – –99 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 – Repeat steps 1–8 to simulate 20 weeks. 10 Machines Existing DemandWeeklyCapacityWeeklySub- RandomProductionRandomCapacityIdleOvertimecontract WeekNumber(hr)Number(hr)HoursHoursHours TABLE B.220-WEEK SIMULATIONS OF ALTERNATIVES Total Weekly average
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. RegularRelative Capacity (hr)Frequency 320 (8 machines) (9 machines) (10 machines)0.30 Average weekly operating machine hours = 360 hours RegularRelative Capacity (hr)Frequency 360 (9 machines) (10 machines) (10 machines) (11 machines) (11 machines)0.30 Simulation Process TABLE B.1RANDOM-NUMBER ASSIGNMENTS TO SIMULATION EVENTS Event Weekly RandomWeeklyRandom Demand (hr)ProbabilityNumbersCapacity (hr)ProbabilityNumbers – – – – – – – – – – – –99 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 – Repeat steps 1–8 to simulate 20 weeks. 10 Machines Existing DemandWeeklyCapacityWeeklySub- RandomProductionRandomCapacityIdleOvertimecontract WeekNumber(hr)Number(hr)HoursHoursHours TABLE B.220-WEEK SIMULATIONS OF ALTERNATIVES Total Weekly average Comparison of 1000-week Simulations 10 Machines11 Machines Idle hours Overtime hours Subcontract hours Cost$1,851.50$1, TABLE B.2COMPARISON OF 1,000 WEEK SIMULATIONS
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Random Numbers Figure B.1
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Best Car Simulation Model Figure B.2 Example B.3
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Inventory Simulation Model Figure B.3
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Flowchart of Passenger Security Process Entrance Arrivals Buffer Sec. Line 1 Work St. Insp. 1 Work St. Insp. 2 Buffer Sec. Line 2 Dec. Pt. DP Work St. Add. Insp. 1 Work St. Add. Insp. 2 Buffer Done Figure B.4
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Results of Passenger Security Process Figure B.5 ElementElementStatisticsOverall TypesNamesMeans Entrance(s)Arrivals Objects entering process Buffer(s) Line 1 Mean inventory 5.97 Mean cycle time 3.12 Line 2 Mean inventory 0.10 Mean cycle time 0.53 Done Final inventory
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process Example B.4
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process X X X X X X X Gate house Not to scale Checkpoint #1 Checkpoint #3 (rarely used) Checkpoint #2 Figure B.6
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process X X X X X X X Gate house Not to scale Checkpoint #1 Checkpoint #3 (rarely used) Checkpoint #2 Figure B.7 12 – 10 – 8 – 6 – 4 – 2 – 0 – |||||| 7:007:107:207:307:407:508:00 Time Arrivals (vehicles/min) STANDARD VEHICLEAVERAGEDEVIATION Cars10 3 Vanpools30 9 Buses5010 INSPECTION TIME (sec)
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process Figure B.8(a)
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process X X X X X X X Gate house Not to scale Checkpoint #1 Checkpoint #3 (rarely used) Checkpoint #2 12 – 10 – 8 – 6 – 4 – 2 – 0 – |||||| 7:007:107:207:307:407:508:00 Time Arrivals (vehicles/min) STANDARD VEHICLEAVERAGEDEVIATION Cars103 Vanpools309 Buses5010 INSPECTION TIME (sec) Figure B.8(b)
To Accompany Krajewski & Ritzman Operations Management: Strategy and Analysis, Seventh Edition © 2004 Prentice Hall, Inc. All rights reserved. Simulation Process X X X X X X X Gate house Not to scale Checkpoint #1 Checkpoint #3 (rarely used) Checkpoint #2 12 – 10 – 8 – 6 – 4 – 2 – 0 – |||||| 7:007:107:207:307:407:508:00 Time Arrivals (vehicles/min) STANDARD VEHICLEAVERAGEDEVIATION Cars103 Vanpools309 Buses5010 INSPECTION TIME (sec) Figure B.8(c)