A make-to-order system has 6 jobs to complete on a single machine. Let tj denote the time (in minutes) to complete job j. We have: t1 = 30, t2 = 25, t3 =35,t4 =40,t5 =15,t6 =30. Assume that the set up time for each job is 10 minutes.

a. What is the average makes pan if jobs are sequenced according to their index (job 1 first, job 2 next etc.)?

b. What is the average makes pan if jobs are sequenced according to a Short- est Processing Time Rule?

c. Assume that jobs have the following due times (in minutes) d1 = 100, d2 = 50, d3 = 200, d4 = 150, d5 = 100, d6 = 200. Find the average tardiness and the number of jobs that are tardy according to the earliest due date rule.

d. Find the average tardiness and the number of jobs that are tardy according to the critical ratio rule.