Flexible Job-Shop Scheduling with Setups and Variable Sublots

In the flexible job shop scheduling problem (FJSP), jobs are always processed in batches. Considering the scheduling objective of minimising the maximum completion time (Cmax), splitting each job into sublots is necessary. However, if the sublots are too small, the time loss caused by the frequent change of jobs on the same machine will increase. Therefore, all processes involved in the FJSP must be split into sublots considering efficiency. This paper proposes a mathematical model with the objective function of minimising the maximum completion time Cmax and the research objective of providing process-level batches and a scheduling technology for the FJSP with setups and sublots. A genetic algorithm is applied to optimise the allocation of the process-level batches on the machines. Finally, a software system for algorithm verification that verifies the validity of our proposed algorithm was developed.