An inspection maintenance model based on a three-stage failure process with imperfect maintenance via Monte Carlo simulation

Inspection is widely used in industry to identify the status of plant and make maintenance decisions. The maintenance models using the delay time concept for optimizing the inspection intervals have been researched for years. However, the three-stage failure process proposed by Wang is closer to reality and provides more modeling options. Imperfect maintenance is common in practice, but not considered based on the three-stage failure process before. An inspection maintenance model based on a three-stage failure process with imperfect maintenance is proposed. The maintenance at minor defect is assumed to be imperfect, but perfect at severe defect. Replacement is implemented at failure. Age reduction concept is utilized to describe the effect of imperfect maintenance. The expected renewed cycle downtime per unit time is derived. Finally, Monte Carlo simulation is presented to show the efficiency of the proposed model.