Machine sharing in manufacturing systems: Total flexibility versus chaining

In this paper, we compare the operational performance of two machine-sharin g configurations: total flexibility and chaining. We show that chaining cap tures most of the benefits of total flexibility while limiting the number o f part types processed on any individual machine to only two. We examine th e relative desirability of the two configurations under varying buffer size s, loading conditions, number of machines, and setup times, as well as for different control policies. For nonzero setups times, we show that chained configurations can outperform fully flexible ones. This particularly is the case when either the number of machines or length of setup times is high. We also find that the effect of the system size on performance diminishes w ith the number of machines. This means that multiple smaller chains can per form almost as well as a single long one. Our results are consistent with t he recent findings of Jordan and Graves (1995), who examined the economic b enefits of chaining relative to full flexibility.