Economic efficiency of the AOQL single sampling plans for the inspection by variables

Abstract

The paper refers to the AOQL (Average Outgoing Quality Limit) single sampling plans when the remainder of the rejected lots is inspected. These rectifying AOQL plans for inspection by variables were created by the author of this paper and published in the Statistical Papers. These new plans were compared with the corresponding Dodge-Romig AOQL plans for inspection by attributes from the economic point of view. Numerical investigations confirm that under the same protection of consumer, the AOQL plans for inspection by variables are in many situations more economical than the corresponding Dodge-Romig AOQL attribute sampling plans. The dependence of the saving of the inspection cost on the input parameters of acceptance sampling (the average outgoing quality limit, the lot size and the process average proportion defective) is analysed in the paper. Moreover, a criterion for deciding if the inspection by variables should be considered instead of the inspection by attributes is suggested in the paper.