Scheduling Policies, Batch Sizes, and Manufacturing Lead Times

In this paper, we examine the impact of scheduling policies on batch sizing decisions in a multi-item production system. We also investigate the joint effect of scheduling policies and batch sizing decisions on production lead times. In particular, we compare the performance of a first come-first-served (FCFS) policy with a group scheduling (GS) policy and study the effect of both on the optimal batch size. We show that a group scheduling policy can lead to significant performance gains, as measured by reduced lead times and higher production rates, relative to the FCFS policy and characterize conditions under which these gains are realized. We also study the impact of the GS policy on other system operating parameters. In particular, we find that using a group scheduling policy eliminates the need for batching, preserves system capacity despite the presence of setups, and accommodates higher product mix variety. These results are shown to be very different from those obtained for the FCFS policy and to have important implications for the management and control of multi-item production facilities. † The author's research is supported by the National Science Foundation under grant No. DMII-9309631.