Dispatching in a multistage job shop where machine capacities are unbalanced

Abstract

In the multistage job shop, several parts are assembled to form sub-assemblies which are then assembled into final products. Job delays may occur due to the lack of capacity and also due to the lack of component parts necessary to form a subassembly. Previous research of similar systems have assumed a balanced capacity. A more realistic assumption is one in which machine capacities are not balanced such that one machine can be identified as a bottleneck. In this paper, the performance of selected dispatching rules in an unbalanced multistage job shop is evaluated to-determine whether the performance is consistent for jobs which are routed through the bottleneck and for jobs which by-pass the bottleneck.