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A set of jobs A, B, C, D, E, F, G, H arrive at time t = 0 for processing on turning and grinding machines. Each job needs to be processed in sequence - first on the turning machine and second on the grinding machine, and the grinding must occur immediately after turning. The processing times of the jobs are given below. Job A B C D E F G H Turning (minutes) 2 4 8 9 7 6 5 10  Grinding (minutes)  6 1 3 7 9 5 2 4 If the makespan is to be minimized, then the optimal sequence in which these jobs must be processed on the turning and grinding machines is

A set of jobs A, B, C, D, E, F, G, H arrive at time t = 0 for processing on turning and grinding machines. Each job needs to be processed in sequence - first on the turning machine and second on the grinding machine, and the grinding must occur immediately after turning. The processing times of the jobs are given below. Job A B C D E F G H Turning (minutes) 2 4 8 9 7 6 5 10  Grinding (minutes)  6 1 3 7 9 5 2 4 If the makespan is to be minimized, then the optimal sequence in which these jobs must be processed on the turning and grinding machines is Correct Answer A-E-D-F-H-C-G-B

Explanation:

By Johnson’s rule of sequencing

1) Mark the minimum time consuming operation for each process

2) It is mentioned in problem to first process turning operation.

Perform that job in machine x which has minimum time consumption.

It is A – E

3) If minimum time is force y then perform that activity from last

Here B is minimum & performed at last.

Final sequence is:

A – E – D – F – H – C – G – B

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