Interstage Transportation Planning in the Deterministic Flow-Shop Environment

In the well-known flow-shop model, we are given a k-stage processing facility and a collection of jobs, each comprising k tasks to be processed in order, one per stage. At every stage, one or more machines are available for processing tasks. We assume that the jobs are independent and that the processing of a task, once begun, cannot be interrupted. In this paper we focus our attention on a critical but largely ignored aspect of flow-shop utilization, namely, that of planning the efficient transportation of work between stages. We therefore assume the existence of a transport, used to ferry jobs from one stage to the next. We devise and formally analyze effective transportation strategies for various situations in this environment that are dependent on the amount of time needed for transportation relative to the amount required for task processing.