Cyclic scheduling for re-entrant manufacturing systems

A scheduling method is elucidated for the re-entrant manufacturing systems, where the process route of a job passes production facilities one or more times. The objectives of the scheduling problem are maximization of the production rate as a primary one and minimization of the throughput time as a secondary one. The method makes the cyclic schedule, where an adequate number of jobs are treated as a lot and the lot is cyclically released into the system. The lot size is determined to maximize the production rate, and a sequencing method of the lots is developed to minimize the throughput time.