| Capacity sensitive lot sizing decisions are an instrument to integrate capacity requirements planning (CRP) and material requirements planning (MRP). MRP is a planning tool for a subset of manufacturing systems, especially hierarchical multi-product, multi-period, and multi-stage production planning and inventory control system. An algorithm is presented, which improves the performance of the total system.;The vehicle used for integration is the planned order release quantity. The algorithm requires minimal deviations from the MRP logic. In this sequential process MRP first issues the action notices, and then the algorithm analyzes the capacity situation in the work centers.;The algorithm scans all planned order releases of lower level items in the action bucket before the orders are released to the shop. For each item a statistic is computed, identifying the degree orders are contributing to capacity problems. This statistic is specific to each individual item. The order causing the highest overload, and the one passing through the lowest utilized work centers are selected for a lot size decrease, respectively an increase. After identifying the candidates, a series of checks analyzes the suitability of the candidates for that change. The lot size of more items can be changed, if several iterations of the algorithm are performed. After each iteration the capacity profiles are updated. The capacity requirements over a short horizon are balanced.;The experiments are performed with FACTORY, a simulation model for MRP research. The design of the experiments consists of a base test identifying the significant environmental parameters, and a main test, which performs a detailed evaluation. The results are evaluated by analysis of variance techniques. |
