Statistical Quality Control, 7th Edition

PART 2

Statistical Methods Useful in Quality Control and Improvement

Statistics is a collection of techniques useful for making decisions about a process or population based on an analysis of the information contained in a sample from that population. Statistical methods play a vital role in quality control and improvement. They provide the principal means by which a product is sampled, tested, and evaluated, and the information in those data is used to control and improve the process and the product. Furthermore, statistics is the language in which development engineers, manufacturing, procurement, management, and other functional components of the business communicate about quality.

This part contains two chapters. Chapter 3 gives a brief introduction to descriptive statistics, showing how simple graphical and numerical techniques can be used to summarize the information in sample data. The use of probability distributions to model the behavior of product parameters in a process or lot is then discussed. Chapter 4 presents techniques of statistical inference—that is, how the information contained in a sample can be used to draw conclusions about the population from which the sample was drawn.