An Integrative Methodology for Simulation of FMS with Alternate Routings

Abstract

This paper reports on a simulation study of a sample FMS with integration of two flexibility types: routing flexibility and scheduling flexibility. The paper describes development of an integrative methodology in which process planning system IMPlanner is integrated with FMS control module. IMPlanner’s rule based process selection system and FMS’s control simulation model perform real-time data exchange in terms of the system status and part routings. FMS is simulated in Arena with four different routing decision policies: a) static best, b) static random, c) routing dynamic, and d) feature focused dynamic and two process selection criteria, machine utilization and machine queue size. Simulation model has been executed on the same data set for four mentioned routing decision policies and for four dispatching policies (FIFO, SPT, SIPT, LIPT). Results of each simulation run in terms of three performance measures; i) resource utilization, ii) throughput, and iii) work in progress (WIP) have been compared in order to determine best routing alternative selection policy, corresponding dispatching policy, and identify the best combination of those two policies. Statistical analysis has been performed on the results to identify the most significant factors that determine the FMS performance in the case of alternate routings.

Article history: Received (14 August 2012); Revised (15. September 2012); Accepted (25 September 2012)