Statistical Methods for Quality Improvement, Third Edition

CHAPTER 1

Introduction

This is a book about using statistical methods to improve quality. It is not a book about Total Quality Management (TQM), Total Quality Assurance (TQA), just-in-time (JIT) manufacturing, benchmarking, QS-9000, or the ISO 9000 series. In other words, the scope of the book is essentially restricted to statistical techniques. Although standards such as QS-9000 and ISO 9000 are potentially useful, they are oriented toward the documentation of quality problems, not the identification or eradication of problems. Furthermore, many people feel that companies tend to believe that all they need to do is acquire ISO 9000 certification, thus satisfying only a minimum requirement.

Statistical techniques, on the other hand, are useful for identifying trouble spots and their causes, as well as predicting major problems before they occur. Then it is up to the appropriate personnel to take the proper corrective action.

The emphasis is on quality improvement, not quality control. On July 1, 1997 the American Society for Quality Control (ASQC) became simply the American Society for Quality (ASQ). The best choice for a new name is arguable, as some would undoubtedly prefer American Society for Quality Improvement (the choice of the late Bill Hunter, former professor of statistics at the University of Wisconsin). Nevertheless, the name change reflects an appropriate movement away from quality control. George Box has emphasized that systems are not stationary and that improvements ...