MODELING AND ANALYSIS OF CLOSED-LOOP PRODUCTION LINES WITH UNRELIABLEMACHINES AND FINITE BUFFERS

The purpose of this paper is to propose an analytical method for the p erformance evaluation of closed-loop production lines with unreliable machines and finite buffers. Such a system consists of a set of K mach ines separated by buffers of finite capacity. There is a fixed number of pallets circulating in the closed loop. We assume that machines hav e deterministic processing times but are subject to failures. Failures and repair times are exponentially distributed. We approximate the be havior of this system by a continuous flow model. The continuous flow model is then analyzed with a decomposition technique, which is simila r to that used for (open) production lines. Numerical experiments are reported that show that the results provided by this method are in gen eral fairly accurate.