Multi-criteria operational control rules in flexible manufacturing systems (FMSs)

SUMMARY

This paper is concerned with the operational control problems in Flexible Manufacturing Systems (FMS) with limited local buffers. Three new process selection rules which can be applied to the FMS with limited local buffers and can flexibly cope with the change of system configuration {machine breakdown, etc.) are developed. In addition, AGV dispatching and AGC route selection rules are also developed for the simultaneous scheduling of jobs and material handling devices. The three new process selection rules (ARD, ARP and ARPD) are then compared with two existing rules (NAR and WINQ) by simulation experiments. The simulation experiments include the six operational control sub-problems for jobs and AG Vs. The multi-criteria performance measures considered simultaneously are makespan, mean flowtime, mean tardiness, maximum tardiness, and system utilization.

The simulation results indicate that ARD gives the best results in four performance measures except for system utilization. Secondly, ARD, ARPD and WINQ rules give significantly better results than ARP and NAR rules in every performance measure. Thirdly, as the production requirements are increased, the differences between [ARD, ARPD, WINQ] and [ARP, NAR] are more significant. Fourthly, the local buffer capacity level of 5 ( = 5) shows the better results for all the performance measures than the capacity level of 3 (q = 3).