Question

Three jobs are to be scheduled on two machines A and B. Assume that the jobs are processed in the

sequence A-B. The processing times are:
Job A B
1 5 4
2 7 7
3 3 5
Draw a Gantt chart that shows the schedule corresponding to the sequence 1-2-3 of the jobs.

Answer 1

Answer:To create a Gantt chart for the sequence 1-2-3, we need to determine the start and finish times for each job on each machine. The processing times for each job on machine A and machine B are given as follows:

Job A B

1 5 4

2 7 7

3 3 5

Based on the given sequence, we need to process job 1 first, followed by job 2 and then job 3. Therefore, we can start by scheduling job 1 on machine A.

Job Machine Start Finish

1 A 0 5

Next, we need to process job 2 on machine B, after job 1 is completed on machine A. Since job 2 takes longer to process on machine A than on machine B, we need to schedule it on machine B first.

Job Machine Start Finish

1 A 0 5

2 B 5 12

Finally, we need to process job 3 on machine A, after job 2 is completed on machine B. Since job 3 takes longer to process on machine B than on machine A, we need to schedule it on machine A first.

Job Machine Start Finish

1 A 0 5

2 B 5 12

3 A 12 15

The resulting Gantt chart is as follows:

Machine A: | 1 | | | 3 |

Machine B: | 2 | |

Time: 0 5 12 15

Therefore, the Gantt chart that shows the schedule corresponding to the sequence 1-2-3 of the jobs is as shown above.