Performance of a Two-Stage Manufacturing System with Control and Communication Overhead

A Markov process model of an externally controlled two-stage manufacturing system is presented. The objective is to examine the effect on system performance of the contention for the resources of the control and communication equipment in the manufacturing system. In the system under consideration, when a new part enters either of the stages, a request-for-instruction message is sent to the control equipment. The stage will then remain idle until a control-instruction message is received from the control equipment. Only then can processing on the part begin. The control and communication equipment is modeled as a queuing system that receives the request-for-instruction messages from the machines, processes these messages, and returns control-instruction messages to the appropriate machine. Part and message processing times can be different and are assumed to have exponential distributions. This model is analyzed to obtain an analytic expression for the throughput (production rate in parts per unit time) of the manufacturing system. Numerical examples that illustrate the effect of model parameters on the system throughput are also presented.