Evaluation of alternative tool combinations in a flexible manufacturing system

Flexible manufacturing systems (FMSs) are often viewed as systems capable of processing a wide variety of parts in random order. The extent to which this is achieved is determined by the number of tools of each type that are active in the system at the same time. Too few tools can result in low system utilization and throughput. Too many tools in the system, however, can increase system cost. A continuous-time Markov chain model and an accompanying cost model are presented in this paper as an analytical means of examining the interrelationships between the number of tools and system performance and evaluating alternative tool combinations. A numerical example is given to illustrate the interrelationships and test the sensitivity of the model. Because of the large number of equations required to be solved, a computer program was written to obtain the results.