Integration of product quality and tool degradation for reliability modelling and analysis of multi-station manufacturing systems

Abstract

The degradation of a tool component at an upstream station may cause the deterioration of the dimensional quality of a downstream workpiece. Meanwhile, the tool failure and its induced system reliability are affected by the incoming product quality from an upstream station. Quality and reliability interaction is thus introduced to address this interdependence in the reliability modeling and analysis of a multi-station manufacturing system. Moreover, an innovative quality and reliability integrated model is developed to describe the complicated propagation and transmission process of the interaction, as well as the information integration between the tool reliability and the product quality across the stations. Three factors are incorporated into the model, namely the tool degradation, the product quality, and the tool failure. An industrial case of a four-station machining process is used to demonstrate the importance and effectiveness of the proposed analytical procedures. Results indicate that the system reliability will be evidently overestimated without consideration of the quality and reliability interaction. Moreover, the presented integrated model suggests early maintenance schedule for the tool failure and its associated machine downtime.

Keywords:

• multi-station manufacturing system
• quality and reliability interaction
• system reliability
• tool degradation
• tool failure

Acknowledgements

The authors greatly acknowledge the editor and the referees for their valuable comments and suggestions that have led to a substantial improvement of the paper. The authors also thank the financial supports from the National Natural Science Foundation of China (NSFC) with the Grant number 50675137 and 70671065, and the Program of Introducing Talents of Discipline to Universities with the Grant number B06012.