Development of New Univariate Process Capability Index for Multistage Wheel Manufacturing System

Abstract

Process capability indices (PCI) are widely appreciated nowadays to measure the performance of a process. They are used to evaluate single or multiple quality characteristics of the process output such as a product or service according to their specifications. Univariate process capability indices are used to analyse a single quality characteristic of a product. Cp, Cpk, Cpm and Cpmk are widely used univariate process capability indices that required significant statistical knowledge to analyse. In this paper, a new univariate process capability index [Ca, Adev, AI] is developed to measure the performance of a multiple-stage locomotive wheel manufacturing system. This index is based on a simple geometric formula and using a process performance monitoring chart. It is less complicated, user friendly and quite suitable for products with one-sided specification limits.