The effects of normal mixtures and autocorrelation on the fraction non-conforming. Issue 10 (26th November 2017)

• Record Type: Journal Article
• Authors: Cohen, Achraf; Amin, Raid
• Is Part Of: Communications in statistics. Volume 46:Issue 10(2017)
• Page Start: 8105
• Page End: 8117
• Publication Date: 2017-11-26
• Subjects: Autoregressive model -- Contaminated distributions -- Mixture distribution -- Process capability -- Quality assurance -- Statistical process control; Primary 62F10 -- Secondary 62F25; Mathematical statistics -- Periodicals; Mathematical statistics -- Data processing -- Periodicals; Digital computer simulation -- Periodicals; 519.5
• DOI: 10.1080/03610918.2016.1263738
• Languages: English
• ISSNs: 0361-0918

Abstract

ABSTRACT: In this article, the effects of mixtures of two normal distributions on the fraction non-conforming are studied in the context of capability analysis. When the output from several processes is mixed, the quality characteristic variables of the resulting mix may result in a normal mixture distribution. This can happen in cases such as monitoring an output from several suppliers, several machines, or several workers. This study considered the independence case and autocorrelated processes for a mixture of two normal distributions, using an autoregressive model of order one, AR(1). It is shown that the true attained process fraction non-conforming (corresponding to specific values for some capability index) can be very different from what is expected when the data are independent normal random variables.