Extensions in multicharacteristics repeat inspection plans

Abstract

In the process of inspection, an inspector is likely to make Type-I and Type-II errors in his judgement about the product quality. This thesis investigates the effect of Type-I and Type-II errors on multicharacteristic repeat inspection plans for critical components. The practicality of inspection models already developed was enhanced by modifying them for the cases where characteristics' defective rates are statistically dependent. Based on the fact that error probabilities are a function of incoming quality, procedures are suggested for estimating the Type-I and Type-II errors for a given incoming quality. These procedures are then utilized to incorporate the dynamic behavior of inspection errors into the repeat inspection models. Results indicate that the effect of errors and statistical dependency are significant and should be incorporated in the design of the inspection plans.