Question

Question 1:

Sequence the jobs shown below by using a Gantt chart. Assume that the move time between machines is one hour. Sequence the jobs in priority order 1, 2, 3, 4.

Job Work Center/Machine Hours                                  Due Date (days)
1	A/3, B/2, C/2	3
2	C/2, A/4	2
3	B/6, A/1, C/3	4
4	C/4, A/1, B/2	3

1. Using finite capacity scheduling, draw a Gantt chart for the schedule (Marks 0.5)
2. What is the makespan? (Marks 0.5)
3. How much machine idle time is there? (Marks 0.5)
4. How much idle time (waiting time) is there for each job? (Marks 0.5)
5. When is each job delivered? (Marks 0.5)
6. Which department is the bottleneck? (Marks 0.5)
7. Calculate the machine utilization? (Marks 0.5)

Answer 1

Solution : b : Machine idle times are : A - 9 hours, B - 8 hours, C - 7 hours

Solution : c : Job completion is well before due dates.

Solution : d : Idle times are as follows.

Solution : e : Better priority schedule : 3-1-2-4 with timespan - 14 hours.