Method for processing n jobs through 3 machines :

As no general method is available for obtaining an optimal sequence in this case.

The earlier method is adopted by Johnson can be extended to cover the special cases where one or both of the following conditions holds:

1) The minimum time on machine A greater than or equal to the maximum time on machine B

2)The minimum time on machine C greater than or equal to the maximum time on machine B The procedure explains here is to replace the problem with the equivalent problem n jobs and 2 fictitious machines denoted by G and H .