New computational experiences on the Hoist Scheduling Problem for cyclic manufacturing of different products.

Abstract

Jobs of two products must receive the same treatments in a production line of tanks. If the size of both batches is equal, we propose a cyclic manufacturing composed of a job from batch 1 and a job from batch 2. A hoist ensures the transfer of the jobs between tanks. The problem consists in the scheduling of hoist movements, which is known as HSP (Hoist Scheduling Problem). There is a comparison between completely separated and mixed production for both batches. The objective is to determine a sequence which minimises the cycle time for two jobs from different products (2-product cycle). We propose a branch-and-bound procedure, which can also be applied to the 2-cycle case for a single product. The model can be extended to ncycles.