A Modified Procedure for Chain Sampling Inspection Plan

Abstract

Chain sampling plans allow significant reductions in sample size under conditions of a continuing succession of lots from a stable process. One condition under which such plans can be applied is that for which lots are expected to be essentially of the same quality. Under this condition, the chain sampling plans are weak in detecting a change in the process state. In this paper, a modified chain sampling plan is presented. The weak point of this plan has been improved upon by attaching importance to the latest information of lot quality by means of a double sampling plan to a submitted lot. In order to compare the proposed sampling plan with the conventional chain sampling plans, simulation results for rapidity of detecting a change in the process state and the operating cost are also presented.