An exact algorithm for calculating the minimum and feasible ranges of cycle time in periodic scheduling with shared resources

Abstract

Cyclic execution of processing activities is a mode of operation frequently employed by batch manufacturers. Periodic scheduling of these cyclic activities is characterized by the cycle time, a variable that represents the time interval between the start of consecutive cycles. The cycle time determines the number of production batches that can be executed in a given time horizon and, consequently, defines the plant throughput. In this paper, an exact, exhaustive algorithm is developed for the calculation of the minimum cycle time and all feasible cycle time ranges in the context of periodic scheduling with shared resources among tasks. The algorithm is first developed for the case where multiple production tasks share a single resource and then extended for the multiple shared resources case. The implementation and efficiency of these algorithms is demonstrated with the use of illustrative and real-world industrial examples.