Selection of Tightened-Normal-Tightened sampling scheme under the implications of intervened Poisson distribution

Azarudheen Shahabudheen,Pradeepa Veerakumari

doi:10.18187/pjsor.v15i1.2351

Abstract

Tightened-normal-tightened (TNT) sampling scheme is one of the most frequently used sampling schemes for making decisions about the finished product lots by examining certain samples from the lots. TNT sampling scheme includes two attribute sampling plans, one for tightened inspection and other for normal inspection along with switching rules. This paper introduces a procedure for TNT by incorporating two single sampling plans (SSP) under the conditions of intervened Poisson distribution (IPD) for the lots which may have a possibility of some intervention during the production process. The paper also assesses the performance of the proposed scheme procedure through its operating characteristic curves. Also, the unity value table is provided for certain parameters of specified producer’s risk and consumer’s risk for shop floor conditions. Further, the efficiency of proposed TNT scheme over the individual SSP under the conditions of IPD is demonstrated with illustrations.

Highlights

Quality control (QC) is a set of procedures used by organizations to achieve the quality parameters or quality goals and continuously improve the organization’s ability to ensure, that the products will meet the quality goals
The statistical methods used to mentor and maintain the quality of products and services are referred as Statistical Quality Control (SQC)
The proposed TNT – (n, c1, c2) sampling scheme is suitable when there is a possibility of intervention during the production process with aim to produce the good products

Summary

Introduction

Quality control (QC) is a set of procedures used by organizations to achieve the quality parameters or quality goals and continuously improve the organization’s ability to ensure, that the products will meet the quality goals. By obtaining an estimated value for ρ, the probability of acceptance can be calculated using equation (9) for given values of n, c and p This implies that TNT with SSP under the conditions of IPD as reference plan is specified by following parameters, i. The OC function of TNT with SSP under the conditions of IPD as reference plan is defined as given in equation (6) where P1 and P2 are probabilities of acceptance of the lots under the tightened and normal inspections which is determined by equation (9) for their corresponding acceptance numbers c1 and c2. Start with tightened inspection with SSP under the conditions of IPD by inspecting every lot submitted in order with sample size n = 23 and acceptance number 1. The unity value np[1] corresponding the acceptance number 6 and intervention parameter 0.15 is 2.8051

Proportion defective

Findings

Conclusion