An integrated model based on statistical process control and maintenance for two-stage dependent processes

ABSTRACT

The close relationship between quality and maintenance of manufacturing systems has contributed to the development of integrated models which use the concept of statistical process control (SPC) and maintenance. This article demonstrates the integration of the Shewhart individual-residual (Z_X − Z_e) joint control chart and maintenance for two-stage dependent processes by jointly optimizing their policies to minimize the expected total costs associated with quality, maintenance and inspection. To evaluate the effectiveness of the proposed model, two stand-alone models—a maintenance model and an SPC model—are proposed. Then a numerical example is given to illustrate the application of the proposed integrated model. The results show that the integrated model outperforms the two stand-alone models with regard to the expected cost per unit time. Finally, a sensitivity analysis is conducted to develop insights into time parameters and cost parameters that influence the integration efforts.

Keywords:

• Control chart
• Economic design
• Integrated model
• Maintenance
• Two-stage dependent process

Mathematics Subject Classification:

• 62D05

Acknowledgments

We thank the anonymous referees, the Editor and Prof. Paul Tu for their valuable comments, criticism and valuable suggestions.

Funding

This work is supported by the National Natural Science Foundation of China (No. 71471088), the China Postdoctoral Science Foundation (No.2014M561655) and the Key Project Grant of National Natural Science Foundation of China (No. 70931002).