Developing and designing of an efficient variables sampling system based on the process capability index

ABSTRACT

Process capability indices (PCIs) are extensively used in the manufacturing industries in order to confirm whether the manufactured products meet their specifications or not. PCIs can be used to judge the process precision, process accuracy, and the process performance. So developing of sampling plans based on PCIs is inevitable and those plans will be very much useful for maintaining and improving the product quality in the manufacturing industries. In view of this, we propose a variables sampling system based on the process capability index C_pmk, which takes into account of process yield and process loss, when the quality characteristic under study will have double specification limits. The proposed sampling system will be effective in compliance testing. The advantages of this system over the existing sampling plans are also discussed. In order to determine the optimal parameters, tables are also constructed by formulating the problem as a nonlinear programming in which the average sample number is minimized by satisfying the producer and consumer risks.

KEYWORDS:

• Application
• decision making
• nonlinear programming
• process capability index
• sampling system
• sampling by variables

2010 MATHEMATICS SUBJECT CLASSIFICATION:

• 62P30
• 90C30
• 90C90

Acknowledgements

The authors would like to thank the anonymous reviewers, the Associate Editor and the Editor for their insightful comments and valuable suggestions which led to improve the presentation of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The second author would like to acknowledge the Department of Science and Technology, Government of India, for supporting the research work financially (FIST) [grant number SR/FST/MSI-107/2015].