Palletizing and Scheduling for Flexible Manufacturing Systems with Multi-fixturing Pallets

Abstract

This study considers a palletizing and scheduling problem for flexible manufacturing systems with multi-fixturing pallets that can load multiple parts at the same time for two distinctive objectives of minimizing the makespan and the total tardiness. The palletizing problem is to determine the set of parts to be loaded on each pallet and the resulting scheduling problem is to determine the allocation/sequence of pallets to process the loaded parts on machines. Practical constraints such as setup worker availability, re-palletizing, central buffer capacity, limited numbers of pallets and fixture type dedicated to each part type are also considered. Due to the complexity of the problem, a solution approach is proposed that decomposes the problem into the sequential sub-problems of determining the set of parts to be loaded on each pallet, the machine for each operation of parts and the sequence of pallets to process their loaded parts on each machine and solves them in sequence. To test performance of the decomposition based solution approach, simulation experiments were done on various test instances, and the results are reported.