In the early 1990s, research began to show that the Japanese production theory, which espouses reduction of machine setup time as a sure way to improve production performance, may be limited. Specifically, it was found that reduction in mean setup times without any change in variance can,...

Utilizing a cyclic queue system, this paper investigates the effect of variance on a multi-item production facility. The variance of setup time, service rate and arrival rate is shown to have a powerful and sometimes paradoxical influence. Reduction in setup time, for example, is usually...