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MINIMIZATION FLOW TIME IN FLEXIBLE DYNAMIC JOB-SHOP SCHEDULING PROBLEM WITH PARALLEL MACHINES

In this paper, we investigate flexible job-shop schedul¬ing with parallel machines in the dynamic manufacturing environment (FDJSPM). In this study, moreover, con¬sidering a dynamic manufacturing environment (causing interval jobs in non-zero time), it contains two kinds of flexibility. Flexibility in the scheduling problems is effec¬tive for improving operational manufacturing systems. Non-flexibility leads to scheduling programs that have problems, like useless loading machines, bottleneck ma¬chines, decreased desirability sources and poor function¬ing of just in time delivery Flexibility arising from par¬allel machines is a special expression of operation flexi¬bility. In this statement, there are one or several iden¬tical machines (PM). Regarding the mentioned flexibil¬ity in manufacturing systems, a job could be processed, not only in several stations (operational flexibility), but. also, on several parallel machines in each station (flexi¬bility of parallel machines. In the present research, the noted scheduling objective is concluded mean flow time. Since the problem is NP- hard, a Genetic Algorithm was applied in salvation. So. the operational proposed GA is compared with a similar approach in the literature (RKGA), where the results demonstrate the inherence of the proposed GA.