DESIGNING QUICK SWITCHING DOUBLE SAMPLING SYSTEM UNDER THE CONDITIONS OF ZERO INFLATED POISSON DISTRIBUTION – SAMPLE SIZE TIGHTENING

Acceptance sampling is an important quality control technique that deals with a systematic procedure on taking a decision whether to accept or reject a product based on the random sample of the product. Quick switching system (QSS) generally involves two levels of inspection, namely normal and tightened inspection, which is usually referred as two plan system. When the products are highly monitored, number of defects will get reduced and the number of non-defects will get increased. Under this situation, Zero Inflated Poisson Distribution is considered to be appropriate. In this paper, the design of a Quick Switching Double Sampling System (QSDSS) is developed under the assumption that the number of non-defects follows a Zero-Inflated Poisson distribution (ZIPD). The proposed system provides a more accurate and effective way to make decisions in acceptance sampling, especially when zero defects occur frequently. The procedure is presented along with the numerical examples to illustrate the selection of an appropriate sampling scheme.