Analytical modeling of closed-loop conveyors with load recirculation

We present closed form analytical results to show the throughput performance of a discrete-window closed-loop conveyors system serving a user-specified set of stations with intermixed load/unload stations. The buffer capacity at the unloading stations is finite; loads that encounter a full buffer (i.e., blocked loads) are assumed to recirculate around the loop to try again. Given the job flow and routing data as well as the configuration of the conveyor loop, we present an analytical approach to approximate the expected overflow of loads on the conveyor (due to blocked loads). Given the expected overflow, we also show the stability condition for the conveyor system.