Exploring the compatibility of dampening procedures and lot-sizing rules in MRP systems under uncertain operating environments

Abstract

There are two important operational procedures, dampening procedures and lot-sizing rules, considered in the design of material requirement planning (MRP) systems. Lot-sizing rules have been extensively studied, and dampening procedures are relatively unfamiliar to MRP users. Dampening procedures are heuristic rules that serve as information filters to screen out excessive rescheduling messages generated by MRP in response to uncertain events occurring within or outside of production systems. There are distinctive characteristics of various lot-sizing rules, such as the just-in-time feature of lot-for-lot rules in which no inventories are carried. Similarly, dampening procedures contain certain operational characteristics that are compatible with that of lot-sizing rules. Due to this compatibility, the system performance of MRP is expected to improve if compatible dampening procedure and lot-sizing rule are used in an MRP system. The purpose of this paper is to explore this interesting compatibility by a simulation experiment to see whether it leads to better system performance under such deviations in operating environments as lead time uncertainty or scrap variations. Research results show that the performance of an MRP system is significantly affected by the dampening procedure and lot-sizing rule selected. We provide a general guideline to help MRP users determine how to select a dampening procedure and lot-sizing rule in tandem in order to generate better system performance in MRP systems.