Models for evaluating the performance of serial and assembly MRP systems

This paper studies the problem of evaluating the level of customer service that can be achieved in serial and assembly production networks operating under MRP. Using results on the relationship between MRP and traditional inventory policies, the paper develops exact and distribution-free expressions for the inventory fluctuations at all stock points of these networks, and uses them to derive analytic models for three customer service measures. All models make use of non-dimensional ratios, which drastically reduce the number of variables involved. These ratios are a direct extension to the multi-level context of previous ratios derived for single-level systems. The present analysis is concluded by an equivalence theorem, which allows the evaluation of the service obtained in two-echelon assembly networks through the direct application of the results obtained for serial networks.