REPRESENTATION OF FLEXIBILITIES IN PROCESS PLANNING IN FMS

Abstract

In flexible manufacturing system, the production of several parts in a single facility sharing constrained resources, and the shop floor disturbances often lead to orders being processed according to a different process plan than was originally prepared. Rescheduling and replanning functions are not catered for in conventional process plans, since they provide only one operation sequence. This inherent lack of flexibility leads to unpredictable behaviour of manufacturing system. So alternate process plans are necessary to increase the flexibility of scheduling activities and allow to remedy quickly to disturbances. In this work, various flexibilities are represented at process planning stage and various alternate process plans are prepared. All these, process plans are ranked using fuzzy approach, known for dealing with imprecise and conflicting objectives. At the end, an attempt has been made to integrate the process planning problem with shop floor scheduling. The proposed scheduling algorithm selects the process plans based on real time shop floor status mainly concerning with due dates and availability of machines.