A user interactive heuristic procedure for solving the multiple product cycling problem

In this paper we consider a lot-sizing model for the manufacture and storage of several products that require processing on a machine with limited production capacity. In addition, the machine can only be dedicated to producing one of these products in a time period and a fixed changeover cost is incurred whenever the machine changes from the production of one product to the production of a different product. A procedure is presented which uses a modified run-out time method to select which product to process next and a single product heuristic algorithm as the lot-sizing module for the selected product. The user is actively involved in resolving infeasibilities and in generating alternate feasible solutions. The procedure was tested on a set of 48 test problems. Each problem was 15 periods in length and consisted of either 2, 3, or 5 products. The best feasible solutions averaged 8.5% above the optimum with a mean CPU solution time of 3.29 s.