A general repeat inspection plan for dependent multicharacteristic critical components

For a normally distributed random variable with unknown mean θ and known variance, optimum double sampling tests of strength (θ1, α, θ2, β) are found and compared with the single sampling test and the SPRT of the same strength. Two optimality criteria are used—minimax ASN and Bayes ASN. Tables of these optimum tests are given. Approximations to optimum double sampling tests for Poisson and binomially distributed variables are discussed.

Optimum Double Sampling Tests of Given Strength I. The Normal Distribution

Multiattribute acceptance sampling plans

Approximate models for the optimum economic design of double sampling plans for attributes are presented. Total cost is assumed to consist of sampling costs, the cost of accepting defective items, and the cost of rejecting good items. This cost is minimized relative to a specified prior distribution of process fraction defective. Models are developed for situations in which rejected lots are either scrapped or subjected to 100 percent inspection with defective items removed. Other variations of the basic model include the incorporation of restrictions among the sampling plan parameters, which may be helpful in improving administrative efficiency, and the use of curtailment on the second sample. Numerical examples for the various models are presented. Model sensitivity to the cost coefficients and to potential misspecification of the parameters of the prior distribution is investigated.

N. Keiding

Papers

Asymptotic Properties of Bayesian Decision Rules for Two Terminal Decisions and Multiple Sampling. I