Lot Sizing in General Assembly Systems with Setup Costs, Setup Times and Multiple Constrained Resources

We introduce a heuristic method for finding good feasible solutions for multi-product lot sizing problems with general assembly structures, multiple constrained resources, and non-zero setup costs and setup times. We evaluate the performance of this heuristic by comparing its solutions to optimal solutions of small randomly generated problems, and to time-truncated Optimization Subroutine Library (OSL) solutions of medium-sized randomly generated problems. In the first case, the heuristic locates solutions averaging 4% worse than optimal in less than 1% of time required by OSL. The heuristic solutions to medium-sized problems are approximately 26% better than solutions OSL finds after 10,000 CPU seconds, and the heuristic finds these solutions in approximately 10% of OSL's time.