A Petri net model of a continuous flow transfer line with unreliable machines

A production line is studied with several machines in series. The machines are separated with finite buffers. They can break down and have to be repaired. Production is assumed to be continuous, i.e. no individual products can be identified. Analytical models for such a system are scarce. Analytical results for the throughput can be obtained only under very restrictive assumptions. The study of longer transfer lines requires either approximation or simulation. A general Petri net model is developed for an n-machine (n−1)-buffer system. Rules to dress up the Petri net transitions are given. The automatic generation of a discrete-event simulation model from the Petri net model is explained. Finally, some potential applications of the Petri net are illustrated.