Scheduling Hybrid Flow Shop Containing Multi-Functional Machines

Multi-functional machine (MFM) is often used in the current manufacturing system. In traditional way, the MFM was treated as single-functional machine (SFM), so the functions of the MFM might be wasted. When the multiple functions of an MFM are utilized to process jobs at several stages in a flow shop, the hybrid flow shop scheduling problem under the environment of MFM (HFSP-MEM) will be induced. A modified genetic algorithm (MGA), which is able to solve the HFSP-MEM directly, is proposed. A case that there is the same processing time of jobs on parallel machines for HFSP-MEM is studied. The criterion for the scheduling is to minimize the makespan of jobs. The MGA is applied to 11 instances from medium scale to large scale. The results show that the makespan will be shortened, if the multiple functions of MFMs are utilized