On modelling and evaluation of corrective and preventive maintenance policies of unreliable manufacturing systems

Due to extensive use and wear of equipment, the occurrence of failures in automated manufacturing systems (AMSs) remains inevitable. However, with maintenance policies, the reliability and availability of such systems can be increased. This paper presents different basic models based on stochastic Petri nets allowing the modeling of the integration of corrective and preventive maintenance in unreliable manufacturing systems and analysis of their effects on system's productivity. In all these models, we make sure that after having undergone a preventive or corrective operation, a resource is functioning normally. This property avoids the execution in the model of an infinite failure loop. Finally, we show how the proposed modeling of these maintenance strategies can be integrated in unreliable controlled manufacturing systems without causing failure-induced deadlocks.