Degradation Analysis of Machine Processing Accuracy for Manufacturing Systems with Effect of Unqualified Products

The machine fault prognosis method by monitoring the manufacturing system dynamical performance has been widely studied recently, which is also the most common and significant problem faced in manufacturing industries. In a manufacturing system, machine is the key component. The dynamic and precise identification of the healthy state of the machine can support the decision making of production operation. In this paper, since the propagation of unqualified products will lead to the deterioration of machine’s processing accuracy, quality of imported products is considered to be an important factor affecting machine’s performance. Considering this practical scenario, a non-homogeneous Poisson process is applied to model the number of quality failures in a manufacturing system, and the log-normal distribution is used to depict the impact strength of unqualified products to a machine. At last, the applicability of the proposed model is discussed for the serial manufacturing system, and an analysis procedure of machine’s accuracy degradation is provided to illustrate its actionability.