The jobs listed below need to be completed.Assume that it is now day 140.If the jobs are sequenced according to the shortest processing time rule,what is the average completion time?
A)47.6 days
B)60.2 days
C)94.0 days
D)2.5 days
E)238.0 days

Question

The jobs listed below need to be completed.Assume that it is now day 140.If the jobs are sequenced according to the shortest processing time rule,what is the average completion time? 
A)47.6 days 
B)60.2 days 
C)94.0 days 
D)2.5 days 
E)238.0 days

Quizplus · Accepted Answer

Using the shortest processing time rule, we schedule the jobs as follows:
- Day 140: Job 4 (processing time = 1 day)
- Day 141: Job 1 (processing time = 2 days)
- Day 143: Job 2 (processing time = 3 days)
- Day 146: Job 3 (processing time = 4 days)
- Day 150: Job 5 (processing time = 5 days)

The completion time for each job is:
- Job 1: 141+2 = 143
- Job 2: 143+3 = 146
- Job 3: 146+4 = 150
- Job 4: 140+1 = 141
- Job 5: 150+5 = 155

The average completion time is the sum of completion times divided by the number of jobs:
(143+146+150+141+155)/5 = 47.6 days.

Therefore, the best choice is A) 47.6 days.

The Jobs Listed Below Need to Be Completed