Arriving time control algorithm for dynamic flexible flow shop problem

This paper considers the dynamic flexible flow shop problem with unrelated parallel machines at each stage and the objective of the problem is to minimize the total earliness and tardiness penalties of all jobs, or to achieve weighted just in time. In previous studies, the job will never change if it has been assigned to a certain machine. Since the schedule should be updated according to the change of current stages, this paper proposes a mechanism that allows the selected machines to be updated for better schedule. Two kinds of arriving time control algorithms are developed. In addition, three improved ways are used to enhance the efficiency of the two algorithms. At last, these eight different approaches have been compared with two classic methods - the stage to stage feedback approach and the earliest to delivery dispatching rule and computational experiences reveal that the proposed approaches are efficient for the targeted problem.