Cellular production lines with asymptotically reliable Bernoulli machines: Performance analysis and lead time control

Cellular lines are production systems consisting of cells comprised of machines performing similar operations. These systems are notorious for having excessively long lead time (LT), often orders of magnitude longer than processing time by all machines in the system. The main goal of this paper is to provide a plausible explanation of this phenomenon and offer methods for LT reduction. To accomplish this, the paper develops a technique for performance analysis of cellular lines with asymptotically reliable Bernoulli machines and uses it to analyze and control LT. It shows, in particular, that robustness of LT is a decreasing function of the number of machines in a cell. Thus, in cells with many machines, small variations in either release rates or machine efficiencies may lead to dramatic increases of LT, if operating points are not selected appropriately. A method for selecting appropriate operating points and, thus, controlling release rates and LT, is provided.