1. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-1 Practice Problems Problem 1: Assume that Susan is a sorority pledge coordinator with four jobs and only three pledges. The table below gives the expected time for each pledge to do each job. If she wishes to minimize the time taken, to whom should she assign which job? Job 1Job 2Job 3Job 4 Alice4938 Barbara7826 Jennifer3457

2. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-2 Practice Problems Problem 1: Assume that Susan is a sorority pledge coordinator with four jobs and only three pledges. The table below gives the expected time for each pledge to do each job. If she wishes to minimize the time taken, to whom should she assign which job? Job 1Job 2Job 3Job 4 Alice4938 Barbara7826 Jennifer3457 Dummy0000 The “dummy” must be added because we have four jobs and only three people.

3. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-3 Practice Problems Problem 1: Assume that Susan is a sorority pledge coordinator with four jobs and only three pledges. The table below gives the expected time for each pledge to do each job. If she wishes to minimize the time taken, to whom should she assign which job? Job 1Job 2Job 3Job 4 Alice0403 Barbara4402 Jennifer0033 Dummy1020 The final table should look like: The set of optimal assignments would then be: Alice - Job 1 Barbara - Job 3 Jennifer - Job 2 Dummy - Job 4 Note that Job 4 does not get done since it is assigned to the “Dummy.”

4. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-4 Practice Problems Problem 2: A custom furniture shop has the five jobs below to be done and they are unsure how to sequence them through the shop. Compare the effect of the scheduling methods (a) FCFS (first come, first served), (b) EDD (earliest due date), and (c) SPT (smallest processing time). Date Promised JobDays to Finish(in days from today) A25 B88 C612 D410 E14

5. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-5 Practice Problems Problem 2: A custom furniture shop has the five jobs below to be done and they are unsure how to sequence them through the shop. Compare the effect of the scheduling methods (a) FCFS (first come, first served), (b) EDD (earliest due date), and (c) SPT (smallest processing time). Date Promised JobDays to Finish(in days from today) A25 B88 C612 D410 E14 FCFS SequenceProcess TimeFlow TimeDue DateLateness A2250 B81082 C616124 D4201010 E121417 Total216933 Average completion time = 69/5 = 13.8 days Average number of jobs in the system = 69/21 = 3.29 jobs Average lateness = 33/5 = 6.6 days Utilization = 21/69 = 30.4%

6. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-6 Practice Problems Problem 2: A custom furniture shop has the five jobs below to be done and they are unsure how to sequence them through the shop. Compare the effect of the scheduling methods (a) FCFS (first come, first served), (b) EDD (earliest due date), and (c) SPT (smallest processing time). Date Promised JobDays to Finish(in days from today) A25 B88 C612 D410 E14 EDD SequenceProcess TimeFlow TimeDue DateLateness E1140 A2350 B81183 D415105 C621129 Total215117 Average completion time = 51/5 = 10.2 days Average number of jobs in the system = 51/21 = 2.43 jobs Average lateness = 17/5 = 3.4 days Utilization = 21/51 = 41.2%

7. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-7 Practice Problems Problem 2: A custom furniture shop has the five jobs below to be done and they are unsure how to sequence them through the shop. Compare the effect of the scheduling methods (a) FCFS (first come, first served), (b) EDD (earliest due date), and (c) SPT (smallest processing time). Date Promised JobDays to Finish(in days from today) A25 B88 C612 D410 E14 SPT SequenceProcess TimeFlow TimeDue DateLateness E1140 A2350 D47100 C613121 B821813 Total214514 Average completion time = 45/5 = 9 days Average number of jobs in the system = 45/21 = 2.14 jobs Average lateness = 14/5 = 2.8 days Utilization = 21/45 = 46.7%

8. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-8 Practice Problems Problem 3: A firm has the following six jobs waiting to be processed. Develop the appropriate sequencing for these jobs using the Critical Ratio criteria. JobHours to ProcessTime Due #40727 #281816 #30644 #4291017 #038515 #9981218

9. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-9 Practice Problems Problem 3: A firm has the following six jobs waiting to be processed. Develop the appropriate sequencing for these jobs using the Critical Ratio criteria. JobHours to ProcessTime Due #40727 #281816 #30644 #4291017 #038515 #9981218 Computed Critical Ratio 7/2 = 3.5 16/8 = 2.0 4/4 = 1.0 17/10 = 1.7 15/5 = 3.0 18/12 = 1.5 Critical Ratio SequenceCritical Ratio #3061.0 #9981.5 #4291.7 #2812.0 #0383.0 #4073.5

10. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-10 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126

11. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-11 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 U

12. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-12 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 R U

13. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-13 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 RV U

14. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-14 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 RSV U

15. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-15 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 RS T V U

16. PowerPoint presentation to accompany Heizer/Render – Principles of Operations Management, 5e, and Operations Management, 7e © 2004 by Prentice Hall, Inc., Upper Saddle River, N.J. 07458 15-16 Practice Problems Problem 4: Our furniture manufacturer has the following five jobs that must go through the two work centers in the table below. What is the appropriate sequence for these jobs? JobHours Required Varnishing (Center 1)Painting (Center 2) R45 S177 T1412 U92 V126 RS T V U