Optimal control of work-in-process with dual limit switches in two-stage transfer line

A full work system is a switch control system developed to control the in-process inventories in serial automated production systems. This paper deals with a full work system which consists of two automated machines that are separated by finite storage. The number of items in the buffer is controlled by dual limit switches. That is, the upper switch is related to the buffer size and the lower one to the restarting point of the preceding machine. For the model developed, the authors analyze the system characteristics and then present a search procedure for finding the optimal control parameters. These parameters would minimize the system costs per unit of time. The system performance is also analyzed through sensitivity analysis.