Note on the problem of scheduling a flexible manufacturing system for just-in-time customers

Abstract

In supplying just-in-time customers, one common industry practice is for the vendor to set up a warehouse near the point of demand. We assume that the plant is a flexible manufacturing system (FMS) where the changeover times between parts of the same family are negligible, but not between parts of different families. Thus the FMS must be configured to produce one family of parts at a time. For each part type, we assume that the vendor makes deliveries to the warehouse at fixed intervals. We examined two related issues: the run length for each part family and the number of deliveries to the warehouse in each cycle. We first showed that it is not necessary for the vendor to produce for each delivery, nor is it desirable to complete the entire production lot before delivery. We then investigated the FMS loading problem for two or more part-families. We developed the expressions for the optimal run length and delivery frequency, (1) when loading the part types sequentially and (2) when loading the part types simultaneously. The resulting models can be shown to be consistent with the classical EOQ model.