Kitting in multi-echelon, multi-product assembly systems with parts substitutable

The kitting problem in multi-echelon, multi-product assembly systems with parts substitutable is to allocate on-hand stock and expected future deliveries to kits to minimize total cost – including job earliness, job tardiness, and in-process holding cost – while considering shop capacity and subassembly precedence restrictions, and parts being substitutable. This class of problem is NP-hard. When dealing with a large instance encountered in industry, in the worst case, it may not be possible to obtain an optimal solution in a reasonable time. In this paper, rules for using part substitutes along with heuristic procedure are presented. Computational results demonstrate that the proposed heuristic outperforms others tested. It is expected that the new heuristic can be applied in resolving large-scale kitting problems encountered in industry to allocate available resources near optimality to enhance schedule performance and to lower the total cost of operating multi-echelon, multi-product assembly systems.