Design and development of two stages mixed sampling plans with the norm of variance and non-conformities

Abstract

The mixed sampling plans are two stages sampling plans in which variable and attribute quality characteristics are used in deciding the acceptance or rejection of the lot. In industries variables and attributes together are used to decide about the acceptance of lots. In industries many products are in measurable dimensions and the quality of the products should not deviate much from the required target. Hence variance of the distributions plays a vital role in the decision making of the lots. Many quality control practitioners insist that in a mixed sampling inspection the first stage sample should be based on the variance criterion for a target-oriented production to reduce the variance. Hence two stages mixed sampling plans are being developed with a variance criterion. This article presents a new algorithm to make a unique decision on the lot for mixed quality control environment. In this paper the sampling plans are developed by considering variable quality characteristics with variance criteria in the first stage and the second stage is dealt with attribute criteria. New efficiency measures are derived and provided. Designing procedure and Illustrations are given.