Exact solution procedures for certain planning problems in flexible manufacturing systems

We address certain production planning problems in a flexible manufacturing environment. We first present a single machine, mixed integer programming model for the part-type selection and the lot-sizing problems over a multi-period planning horizon. Available machine time and tool magazine capacities are the system constraints in this model. The single machine model is then extended to include multiple machines. In the extended model, in addition to the part-type selection and the lot-sizing decisions, we also address the machine loading decision. We present exact branch-and-bound procedures based on linear programming relaxations for the two models. Results of computational experiments are also reported.