Abstract
Material requirements planning (MRP) systems have become a dominant method in production scheduling and inventory control over the last decade. An MRP is a very complicated information system. It needs to be updated frequently in order to reflect unplanned events, such as machine breakdowns, that exist within or outside the production system. However, the resultant frequent disruption of open orders is a major operational problem of MRP systems, which is generally referred to as 'system nervousness'. MRP system nervousness is caused by various operating variables and environmental factors. The purpose of this paper is to evaluate the impact of operating environments, external or internal, on MRP system nervousness. Several studies have addressed the effectiveness of alternative strategies for reducing MRP system nervousness in a number of operating environments. In this study, a factory simulation is used as an experimental vehicle to investigate the impact on M R P system nervousness of various factors, such as the tightness of capacity utilization and the lot-sizing algorithm used. Based on this study, a set of guidelines is presented which allow MRP users to select an appropriate dampening strategy to cope with system nervousness in face of their operating environments.