This work consists of studying a practical problem that arises from a foundry, which has only one furnace operating at each period, which is the production bottleneck. Several moulding machines produce moulds for a known demand of different types of items, which must be made with different alloys. For each period, the production programming has two important and linked decision levels: 1) which alloys should be produced in the furnace, and 2) the quantity of each item to be produced in each moulding machine. In an earlier study, a single-level, multi-item, capacitated, parallel machine lot-sizing model was proposed. In this work, that model has been extended considering setup cost and backlog of orders, as well as the solution method. This approach provides the decision maker with possible arrangements on demand, in case of backlogging.
mixed integer programming; lot sizing and scheduling; foundries
