Exclusive Content & Downloads from ASQ

ANSI/ASQC Z1.4 Performance Without Limit Numbers

Summary: ANSI/ASQC Z1.4 is a widely used attributes acceptance sampling system. The latest revision of the standard makes optional the use of limit numbers for reduced inspection. This paper presents a Markov model of the sampling system without limit numbers. The model is valid for all single, double and multiple sampling schemes. Closed form, analytical results are developed for various performance measures. The maximum average run length on normal inspection is found to be only 12.7 lots, which leads to excessive switching between plots when quality is worse than the AQL.

Anyone with a subscription, including Site and Enterprise members, can access this article.

Other Ways to Access content:

Join ASQ

Join ASQ as a Full member. Enjoy all the ASQ member benefits including access to many online articles.

Subscribe to Journal of Quality Technology

Access this and ALL OTHER Journal of Quality Technology online articles. You'll also receive the print version by mail.

  • Topics: Sampling
  • Keywords: Sampling,Acceptable quality level (AQL),Markov chains,Switching rules
  • Author: Grinde, Roger B.; McDowell, Edward D.; Randhawa, Sabah U.
  • Journal: Journal of Quality Technology