Question

Five jobs are waiting for processing through two work centers. Their processing time in minutes) at each work center is contained in the table below. Each job requires work center Sigma before work center Delta. According to Johnson's rule, what sequence of jobs will minimize the completion time for all jobs? Job Sigma Delta LOED> O A R-S-T-U-V OB. R-V-T-S-U OC. V-R-U-S-T OD. V-S-U-T-R O E. S-U-T-V-R

Answer 1

Johnson’s Rule is:

1. From the list of unscheduled jobs, select the one with the shortest processing time in either work center.
2. If the shortest time is at the first work center, do the job first in the schedule otherwise do the job last in the schedule.
3. Remove the job assigned in Step 2 from the list of unscheduled jobs.
4. Repeat steps 1,2 and 3 filling in the schedule from the front and the back until all jobs have been scheduled.

Therefore,

Sequence of jobs should be :

        V - S -U- T   -    R

ANSWER : D) V-S-U-T-R