Imperfect Economic Production Quantity Models Under Predictive Maintenance And Reworking

Due to the popularity of Industry 4.0, many companies have begun to develop intelligent production systems and perform predictive maintenance. These innovations monitor production systems by using sensors and data analysis, and they maintain production systems before they become 'out of control'. This paper develops imperfect economic production quantity (EPQ) models that consider predictive maintenance and reworking of defective products. The objective is to determine the optimal predictive maintenance effort and production runtime and minimise the total expected cost. Two situations are considered: (1) the production system continuously producing products when it shifts to the out-of-control state and (2) the production system stops producing when it shifts to the out-of-control state. We formulate the cost functions and provide algorithms to solve the problems. A numerical study is conducted to illustrate our models and the solution procedure. We also discuss the influence of system parameters (such as predictive and corrective maintenance costs) on the predictive maintenance effort and production runtime decisions and total cost. The results could be used by managers as a reference when consider imperfect economic production quantity models under predictive maintenance and reworking.