Table J.3
Six jobs have just arrived at workstation 017;which has been idle.All the pertinent data are given in the following table.The shop works eight hours per day.It is now time zero.

-Use the information in Table J.3.If the critical ratio rule is used,what is the average past due?
A)fewer than or equal to 1 hour
B)greater than 1 but fewer than or equal to 4 hours
C)greater than 4 but fewer than or equal to 6 hours
D)greater than 6 hours

Question

Table J.3
Six jobs have just arrived at workstation 017;which has been idle.All the pertinent data are given in the following table.The shop works eight hours per day.It is now time zero.
 
-Use the information in Table J.3.If the critical ratio rule is used,what is the average past due?
A)fewer than or equal to 1 hour 
B)greater than 1 but fewer than or equal to 4 hours 
C)greater than 4 but fewer than or equal to 6 hours 
D)greater than 6 hours

Quizplus · Accepted Answer

Using the critical ratio rule:

Job A: (5 + 45) / 45 = 1.22
Job B: (10 + 20) / 20 = 1.5
Job C: (5 + 30) / 30 = 1.17
Job D: (25 + 20) / 20 = 2.25
Job E: (30 + 50) / 50 = 1.6
Job F: (20 + 10) / 10 = 3

The job with the lowest critical ratio is Job C, which should be processed first. Then we have:

Job C: 30 minutes
Job A: 50 minutes
Job B: 20 minutes
Job E: 50 minutes
Job F: 10 minutes
Job D: 20 minutes

The total processing time is 3 hours and 40 minutes, which is greater than the available 8 hours. Therefore, the average past due time will be greater than 4 but fewer than or equal to 6 hours. Therefore, the answer is C.

Table J.3 Six Jobs Have Just Arrived at Workstation 017;which Has Been