Multi-product scheduling on a single machine: A case study

Abstract

The multi-product single machine scheduling problem is not new in the literature. The usual method of solution offered consists of determining the Economic Batch Quantities (EBQ) and then finding an acceptable way of scheduling these quantities on the single facility. However, past experience shows that EBQs cannot be scheduled in the same solution because of some limitations, mostly when a product produced earlier has run out of stock. Eventually, an acceptable batch quantity has to be selected that will satisfy a set of given conditions or objectives. Before calculating the EBQ, it is generally necessary to determine the main cost factors, namely, the set up cost of the machine and the inventory holding cost of the product. A case study is described in this paper, in which the scheduling was carried out without the determination of these costs. However, deviations from this solution may have to be considered. A simple way of calculating the costs incurred by such deviations is described.