Quality in Production—Process Control I

This chapter discusses the quality methods used during the production stage of the cycle. The major tools used in the production stage are the control charts, of which several different types exist to handle the different types of product characteristics and process variables encountered in real-world processes. The measures for evaluating process capability, the ability of a process to produce products within customer's specifications, are covered, as are the methods for assessing the capability of measuring instruments. The chapter examines the topics in process control that are considered essential for the day-to-day process control work in a production or service environment. The most popular combination used to control a measurement is that of X-chart and R-chart, the former to control the process mean and the latter to control the process variability. If the variability in the characteristic is to be controlled, then the standard deviation, or a similar measure suitable to estimate the variability, will be computed and plotted.