Dan O’Leary to conduct a workshop on Attribute Acceptance Sampling for the Worcester ASQ on April 16

Title: Attributes Acceptance Sampling – Understanding How it Works

Abstract: Attribute sampling is a powerful tool in the Quality Engineer’s toolkit. This presentation makes clear how these sampling plans work. We explain how the Operating Characteristic (OC) curve describes lot acceptance and define the key points on the curve. We show how to calculate the curve, illustrating simple methods using Excel. With this background, we examine two popular sampling plans: ANSI/ASQC Z1.4 and c=0. Z1.4 contains single, double, and multiple sampling plans. We show the tradeoff between these plans in terms of risk and cost. The standard also contains switching rules, which can help you reduce inspection costs. We also describe the c=0 plans and compare them with the corresponding Z1.4 plans. These plans have advantages and disadvantages, which are easy to understand by comparing the OC curves.