ABSTRACT
Process capability indices have been widely used in industry to determine if a process is capable of manufacturing good-quality items. Let Y be an appropriately chosen quality characteristic. We assume that Y has a normal distribution with mean μ and variance σ2, and denote Y ∽ N (μ, σ2). When a one-sided upper specification limit U is given, an item is nonconforming if Y exceeds U. The process capability index CPU is defined as: CPU = U − μ 3 σ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003067559/155d9bbf-5d82-497a-b066-eb34d7a7f993/content/eq7.tif"/>
