When minimizing the make span, at least one of the
optimal solutions is a semi-active (no operation can started
earlier without violating the technological constraints [9]. For
this reason, every time when make span is optimized, a
schedule can be described by the processing orders of
operations on the machines [10]. Some assumptions used in
this research are:
1) The jobs are independent and consist of strictly ordered
operation sequences.
2) No priorities are assigned to any job or operation.
3) Job pre-emption is not allowed.
4) A given operation can be performed by one or more
non-identical machines (called alternative machines).
5) The setup times are independent of the operation
sequence and are included in the processing times.
6) The transfer time between operations will be occurred
whenever there is a machine changes for each job.
The completion time of each job will be follows the
equation (3). The transferring time will be included based on
the total transfer time between operation perform in each job.