Abstract
The coefficient of variation (CV) is an important quality parameter to measure the product quality. A variable repetitive group sampling (VRGS) plan based on the CV is developed in this paper when the quality characteristic follows normal distribution. The optimal plan parameters of the proposed VRGS plan are determined by satisfying the commonly used producer's risk and consumer's risk at the same time by minimizing the average sample number (ASN) and then tabulated for various combinations of acceptance quality level and limiting quality level. Moreover, the efficiency of the proposed VRGS plan is compared with the single sampling plan and the two-stage sampling plan. The results show that proposed plan has better performance than existing sampling plans in terms of ASN. Finally, the proposed VRGS plan is illustrated with an industrial example.