Question

You have been asked to sequence the following jobs. Task A must always be done before Task B. Using Johnson's Rule, in what order will you do the jobs?

Job	Task A	Task B
A	3	6
B	7	6
C	5	2
D	5	8
E	4	7
F	9	3
G	1	4

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.

Accordingly order in which tasks should be performed is :

G -A- E- D- F -B - C