Johnson's Rule
1. What is Johnson's Rule
2. Objectives of Johnson's Rule
3. Conditions
for the Johnson's Rule
4. Steps Involved
In Johnson's Rule
5. Example with Solution
6. Simulation
1. What is
Johnson's Rule
Johnson's
Rule is a technique that
can be used to minimise the completion time for
a group of jobs that are to be processed on two machines or at two successive work
centres.
2. Objectives of Johnson's Rule
The Objectives of the Johnson's Rule are:
 To minimise the processing time for sequencing a group of
jobs through two work centres. 
 To minimise the total idle times on the machines. 
 To minimise the flow time from the beginning of the first
job until the finish of the last job.

3. Conditions for the Johnson's Rule
In order for the technique to be used, several conditions must be satisfied:
 Job time(including setup and processing) must be known and
constant for each job at each work centre. 
 Job times must be independent of the job sequence. 
 All jobs must follow the same twosetup work sequence. 
 Job priorities cannot be used.

4. Steps Involved In Johnson's Rule
Johnson's Rule involves four steps:
1. All jobs are to be listed,
and the processing time of each machine is to be listed.
2. Select the job with the
shortest processing time.
If the shortest time lies on the first
machine/work centre, the job is scheduled
first.
If the shortest time lies on the second
machine/work centre, the job is scheduled
at the end.
Ties in activity times can be broken arbitrarily.
3. Once the job is scheduled,
go to step 4.
4. Repeat steps2 and step3 to
the remaining jobs, working towards the centre of the
sequence.
Example with Demo
solution
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Rule Simulation]
