# Operations Management Exam 3

Topics: Time, Critical path method, Present Pages: 10 (1812 words) Published: December 30, 2012
Question 1
A single machine work center has five jobs assigned to it. They are labeled, in the order of their arrival in the shop, as jobs A, B, C, D and E. The work center may work on only one job at a time and must complete any job it starts before starting another job. Job A has a processing time of 6 days and is due to the customer in 9 days. Job B has a processing time of 2 days and is due in 16 days. Job C has a processing time of 4 days and is due in 10 days. Job D has a processing time of 3 days and is due in 7 days. Job E has a processing time of 5 days and is due in 12 days. Using the first-come-first-served priority rule, what is the number of late (tardy) jobs? Answer

0 (zero)

1

2

3

4
5 points
Question 2
A single machine work center has five jobs assigned to it. They are labeled, in the order of their arrival in the shop, as jobs A, B, C, D and E. The work center may work on only one job at a time and must complete any job it starts before starting another job. Job A has a processing time of 6 days and is due to the customer in 9 days. Job B has a processing time of 2 days and is due in 16 days. Job C has a processing time of 4 days and is due in 10 days. Job D has a processing time of 3 days and is due in 7 days. Job E has a processing time of 5 days and is due in 12 days. Using the shortest (earliest) due date rule, what is the average completion (flow) time of all jobs? Answer

4.0

12.6

2.6
5 points
Question 3
A single machine work center has five jobs assigned to it. They are labeled, in the order of their arrival in the shop, as jobs A, B, C, D and E. The work center may work on only one job at a time and must complete any job it starts before starting another job. Job A has a processing time of 6 days and is due to the customer in 9 days. Job B has a processing time of 2 days and is due in 16 days. Job C has a processing time of 4 days and is due in 10 days. Job D has a processing time of 3 days and is due in 7 days. Job E has a processing time of 5 days and is due in 12 days. Using the shortest processing (operating) time priority rule, what will be the average tardiness of these orders? Answer

2.6

2.0

3.0
5 points
Question 4
A single machine work center has five jobs assigned to it. They are labeled, in the order of their arrival in the shop, as jobs A, B, C, D and E. The work center may work on only one job at a time and must complete any job it starts before starting another job. Job A has a processing time of 6 days and is due to the customer in 9 days. Job B has a processing time of 2 days and is due in 16 days. Job C has a processing time of 4 days and is due in 10 days. Job D has a processing time of 3 days and is due in 7 days. Job E has a processing time of 5 days and is due in 12 days. Using the shortest processing (operating) time priority rule, what will be the average number of jobs in the system? Answer

5

4

3

2.5
5 points
Question 5
A machine shop has two machines, M1 and M2. Four jobs A, B, C, and D need to be processed through machines M1 first and M2 second. Job A will take one hour on machine M1 and three hours on machine M2. Job B will take three hours on M1 and two hours on M2. Job C, takes seven hours on M1and three hours on M2. Job D, requires five hours on M1 and one hour on M2. Using Johnson's rule, in what order should these jobs be done? Select one of the following answers. Answer

ABCD

ACBD

DABC

DACB
5 points
Question 6
Consider the following data for a five-job, 2-machine, flow-shop problem. Find the value of make-span (minimum time to complete all jobs) using the sequence ABCDE. (Note: It is suggested that you draw the Gantt chart first.)

TimeTime
JobM1M2
A12
B42
C13
D54
E35

16

19

20

30
5 points
Question 7
Which of the following is a measure of whether the job is done ahead of, on, or...