An examination of dampening procedures considering rescheduling costs

System nervousness in material requirements planning (MRP) systems has been receiving considerable attention recently. Several strategies are suggested to reduce MRP system nervousness. This paper examines one of these nervousness-reduction methods, dampening procedures. Dampening procedures are non-inventory-oriented, which screen out insignificant rescheduling messages generated by MRP systems so as to reduce schedule disruptions. The cost of rescheduling is incorporated as a component of total cost to evaluate the effectiveness of alternative dampening procedures by a simulation experiment under such operating environments as the presence of production uncertainty, different capacity utilization, and different rescheduling efforts. The dampening procedures tested are the static dampening procedure, automatic rescheduling procedure, and cost-based dampening procedure. The results indicate that the static and cost-based dampening procedures outperform the automatic rescheduling procedure under most operating conditions considered in the study. Furthermore, the relative performance of the static and cost-based procedures depend on the difficulty of rescheduling efforts involved and the lot-sizing rule used.