Developing a variables two-plan sampling system for product acceptance determination

ABSTRACT

In this paper, a variables tightened-normal-tightened (TNT) two-plan sampling system based on the widely used capability index C_pk is developed for product acceptance determination when the quality characteristic of products has two-sided specification limits and follows a normal distribution. The operating procedure and operating characteristic (OC) function of the variables TNT two-plan sampling system, and the conditions for solving plan parameters are provided. The behavior of OC curves for the variables TNT sampling system under various parameters is also studied, and compared with the variables single tightened inspection plan and single normal inspection plan.

KEYWORDS:

• Decision making
• Fraction of defectives
• Normal inspection
• Quality control
• Tightened inspection

MATHEMATICS SUBJECT CLASSIFICATION:

• Primary 62F03
• Secondary 62P30

Acknowledgments

The authors would like to thank the Editors and anonymous referees for their helpful comments and careful readings, which significantly improved the presentation of this paper.

Funding

This work was financially supported by the Ministry of Science and Technology, Taiwan under Grant No. MOST 103-2221-E-007-103-MY3.