Scheduling random flexible manufacturing systems with dynamic environments

American designers are designing more flexibility into flexible manufacturing systems (FMSs). However, there has been little research on the scheduling of these more flexible systems. This study adds insights into how these systems should be scheduled and increases the present understanding of the influences of routing flexibility. A few American FMSs use off-line schemes for scheduling but most use real-time schemes. This research compares seven real-time and two off-line scheduling schemes for a random flexible manufacturing system. The results indicate that full advantage can be taken of these more flexible systems if off-line schemes are used. The scheme that takes the greatest advantage of increased flexibility is an off-line scheme that decomposes the scheduling problem. As flexibility increases this scheme is able to schedule more output and reduce the average flow time of parts, and it accomplishes this with little additional computational effort.