Question

A shoe repair operation uses a two-step sequence that all jobs in a certain category follow. All jobs can be split in half at both stations. For the group of jobs listed: JOB TIMES (minutes) A B C D E Workstation A 27 18 70 26 15 Workstation B 45 33 30 24 10 Click here for the Excel Data File a. Find the sequence that will minimize total completion time. b. Determine the amount of idle time for workstation B.

Answer 1

1. The sequence that will minimize the total completion time is sequence 4. B-A-C-D-E.

2. The determination of the amount of idle time for Workstation B is 37 minutes.

Johnson's Sequencing Rule:

According to Johnson's sequencing rule, start listing jobs with minimum completion time first.

If the job occurs at Workstation A, list it on the left side.  If the job occurs at Workstation B, list it on the right side, as below:

Data and Calculations:

JOB TIMES (minutes)     A     B    C     D     E

Workstation A                27   18   70   26   15

Workstation B                45  33   30   24   10

The first job with a minimum completion time is Job E at Workstation B.

The second job with a minimum completion time after Job E is Job B at Workstation A.

The third job with a minimum completion time after Job B is Job D at Workstation B.

The fourth job with a minimum completion time after Job D is Job A at Workstation A.

The last job is Job C at Workstation B.

The sequence that minimizes total completion time is as follows:

        B         A            C              D          E

A                                                                    B

Calculation of Idle Time at Workstation B:

Job       Workstation A               Workstation B                  Idle Time

              In           Out                  In           Out               Workstation B

B            0            0+18 =  18       18        18+33 = 51                   18

A          18           18+27 = 45       51        51+45 = 96                  19

C         45          45+70 = 115      115      115+30 = 145                 0

D        115          115+26 = 141     145     145+24 = 169                 0

E        141           141+15 = 156    169     169+10 =  179                 0

Total Idle Time at Workstation B =                                         37 (18 + 19)

Thus, the sequence that minimizes the total completion time is sequence 4, while the idle time at Workstation B is 37 minutes.

Learn more about Johnson's job sequencing rule at https://brainly.com/question/6484513 and https://brainly.com/question/15970710

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Question Completion with Answer Options:

1. A-B-C-D-E

2. E-D-B-C-A

3. D-C-B-A-E

4. B-A-C-D-E

5. C-A-B-D-E