A Method for Distributing Tools in 2-Machine Flowshop-Type FMS (3rd Report, A Case of Completely Separated Functional FMS with Precedence Constraints on Job Operations)

Abstract

A method for distributing tools to each machine in a 2-machine flowshop-type FMS without duplicated tools is proposed when there are precedence constraints on job operations. All of the tools required for processing various kinds of jobs in the FMS are allocated to each machine according to the from-to chart which represents the technical precedence constraints on the tools. Some simulation results show that when the number of jobs is large and the frequency of utilization of each tool is uniformly distributed, the utilization of completely separated functional FMS (CSF-FMS) designed by this method is as high as that of the full functional FMS (FF-FMS) where each machine has all of the tools. It is also made clear that when the number of jobs is small and the number of job operations is exponentially distributed, the utilization of the CSF-FMS is far less than that of the FF-FMS.