If the following jobs are sequenced according to the SPT rule then the maximum job tardiness (in days)is (assume zero for today's date)

A)26 days
B)16 days
C)10 days
D)5.2 days

Question

If the following jobs are sequenced according to the SPT rule then the maximum job tardiness (in days)is (assume zero for today's date)

A)26 days 
B)16 days 
C)10 days 
D)5.2 days

Quizplus · Accepted Answer

SPT (Shortest Processing Time) rule means the job with the shortest processing time is scheduled first. 
The jobs and their processing times are:
Job A - 5 days 
Job B - 7 days 
Job C - 10 days 
Job D - 12 days 
Job E - 15 days

By scheduling the jobs with the SPT rule, the sequence would be:
A, B, C, D, E

Calculating the due dates (assuming zero for today's date), we get:
Job A - due date of 5 days 
Job B - due date of 12 days 
Job C - due date of 22 days 
Job D - due date of 34 days 
Job E - due date of 49 days

Therefore, the maximum job tardiness would be 16 days (Job E finishing 16 days after its due date).

If the Following Jobs Are Sequenced According to the SPT