A Study and Construction of Tightened- Normal- Tightened Sampling Scheme by Attributes under the Conditions of Zero-Inflated Poisson Distribution

Abstract

No defect has found in the sampling inspection frequently and the manufacturing process is well fitted and maintained proper way. The suitable probability distribution of the number of defects is a zero-inflated Poisson (ZIP) distribution. This article gives a construction of Tightened- Normal- Tightened (TNT) sampling scheme by attributes using unity values are considered, under the conditions of zero-inflated Poisson distribution, when the number of defects follows a ZIP distribution. The operating characteristic (OC) function of the TNT sampling Scheme was derived. Scheme parameters were obtained for some sets of values of (P_N, P_T, p₁, α, p₂, β). Numerical illustrations are given to describe the determination of TNT by attributes under ZIP distribution and to study its performance in comparison with TNT by attributes under Poisson distribution.