Measuring uncertainties in Materials Requirement Planning environments

Many uncertainties in Material Reqirements Planning (MRP) systems are treated as ‘controllable’ elements, with a variety of buffering, dampening and other approaches being used to cope with them. However, such approaches are often found wanting, forcing enterprises into emergency measures to ensure delivery performance. Based upon the results of a questionnaire survey, this paper analyses the uncertainties in the aggregate, intermediate and operational levels that affect customer delivery performance in MRP environments. These uncertainties have been quantified and the relative importance to performance has been investigated. The results also show the widespread use of buffering, dampening and other approaches to provide a level of delivery reliability. It is contended that by concentrating on minimising the effects of the uncertainties, the underlying causes have not been addressed, resulting in sub-optimisation of system performance.