The Total Quality Approach to Quality Management i QUALITY IMPROVEMENT (formerly entitled Quality Control) Ninth Edition PDF

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The Total Quality Approach to Quality Management i QUALITY IMPROVEMENT (formerly entitled Quality Control) Ninth Edition Dale H. Besterfield, Ph.D., P.E. Professor Emeritus College of Engineering Southern Illinois University Boston Columbus Indianapolis New York San Francisco Upper Saddle River Ams...

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The Total Quality Approach to Quality Management

QUALITY IMPROVEMENT (formerly entitled Quality Control)

Ninth Edition

Dale H. Besterfield, Ph.D., P.E. Professor Emeritus College of Engineering Southern Illinois University

Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montreal Toronto Delhi Mexico City São Paulo Sydney Hong Kong Seoul Singapore Taipei Tokyo

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Editorial Director: Vernon R. Anthony Acquisitions Editor: David Ploskonka Editorial Assistant: Nancy Kesterson Director of Marketing: David Gesell Executive Marketing Manager: Derril Trakalo Senior Marketing Coordinator: Alicia Wozniak Marketing Assistant: Les Roberts Senior Managing Editor: JoEllen Gohr Associate Managing Editor: Alexandrina Benedicto Wolf Production Project Manager: Maren L. Miller Production Manager: Laura Messerly Art Director: Jayne Conte Cover Designer: Suzanne Duda Cover Art: Anna Velichkovsky/Fotolia Media Director: Karen Bretz Full-Service Project Management: Sandeep Rawat/Aptara®, Inc. Composition: Aptara®, Inc. Printer/Binder: Edwards Brothers Cover Printer: Lehigh-Phoenix Color/Hagerstown Text Font: Minion Credits and acknowledgments for material borrowed from other sources and reproduced, with permission, in this textbook appear on the appropriate page within the text. Microsoft® and Windows® are registered trademarks of the Microsoft Corporation in the U.S.A. and other countries. Screen shots and icons reprinted with permission from the Microsoft Corporation. This book is not sponsored or endorsed by or affiliated with the Microsoft Corporation. Copyright © 2013, 2009, 2004, 2001, 1998 by Pearson Education, Inc., publishing as Prentice Hall. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07458, or you may fax your request to 201-236-3290. Many of the designations by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps. Library of Congress Cataloging-in-Publication Data Besterfield, Dale H. Quality improvement / Dale H. Besterfield.—9th ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-0-13-262441-1 ISBN-10: 0-13-262441-9 1. Quality control. I. Title. TS156.B47 2013 658.5’62—dc23

10 9 8 7 6 5 4 3 2 1 ISBN 10: 0-13-262441-9 ISBN 13: 978-0-13-262441-1

PREFACE This book was formerly titled Quality Control and is now titled Quality Improvement to reflect the concept of improvement rather than control. In 1997 the American Society for Quality Control changed its name to the American Society for Quality as an indication of this change in philosophy. The text has been reworked to focus on the quantitative aspects of improvement. Chapters entitled “Lean Enterprise,” “Six Sigma,” “Experimental Design,” and “Taguchi’s Quality Engineering” have been added. A fundamental, yet comprehensive, coverage of statistical quality improvement concepts is provided. A practical state-of-the-art approach is stressed throughout. Sufficient theory is presented to ensure that the reader has a sound understanding of the basic principles of quality control. The use of probability and statistical techniques is reduced to simple mathematics or is developed in the form of tables and charts. The book has served the instructional needs of technology and engineering students in technical institutes, community colleges, and universities. It has also been used by undergraduate and graduate business students. There is enough material for two courses. Professional organizations and industrial corporations have found the book an excellent training and instruction manual for production, quality, inspection, marketing, purchasing, and design personnel. Quality Improvement begins with an introductory chapter covering quality improvement tools, which is followed by chapters “Lean Enterprise” and “Six Sigma.” Readers will find that the first three chapters can be covered and comprehended before beginning to work with the statistical chapters. Subsequent chapters discuss qualitative aspects of statistical process control, fundamentals of statistics, control charts for variables, additional statistical process control (SPC) techniques for variables, fundamentals of probability, and control charts for attributes. The final group of chapters describes acceptance sampling, reliability, management and planning tools, experimental design, and Taguchi’s quality engineering.

STUDENT DATA FILES

DOWNLOAD INSTRUCTOR RESOURCES FROM THE INSTRUCTOR RESOURCE CENTER An online Instructor’s Manual is available for this book. To access supplementary materials online, instructors need to request an instructor access code. Go to www. pearsonhighered.com/irc to register for an instructor access code. Within 48 hours of registering, you will receive a confirming e-mail including an instructor access code. Once you have received your code, locate your text in the online catalog and click on the Instructor Resources button on the left side of the catalog product page. Select a supplement, and a login page will appear. Once you have logged in, you can access instructor material for all Prentice Hall textbooks. If you have any difficulties accessing the site or downloading a supplement, please contact Customer Service at http://247pearsoned.custhelp.com/. I am indebted to the publishers and authors who have given permission to reproduce their charts, graphs, and tables. I thank the following for reviewing the manuscript: Hans Chapman, Morehead State University; Thomas C. DeCanio, New York Institute of Technology; Dr. Steve Dusseau, Indiana Institute of Technology; Susan Ely, Ivy Tech Community College; Dan Fields, Eastern Michigan University; Dana Johnson, Michigan Technological University; Ali E. Kashef, The University of Northern Iowa; Dale Schrimshaw, Northeastern State University; Carrie Steinlicht, Ph.D., South Dakota State University; Amer Zaza, Alabama A&M University; and Donna Zimmerman, Ivy Tech Community College. I am also grateful to the Chinese and Spanish translators who converted the English text into those languages. Professors, practitioners, and students throughout the world have been most helpful in pointing out the need for further clarification and additional material in this ninth edition. Dale H. Besterfield

Microsoft® Excel data files are available for student use on the Companion Website at www.pearsonhighered.com/ besterfield.

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CONTENTS 1 Introduction to Quality Improvement 1

7 Additional SPC Techniques for Variables 95

Objectives 1 Introduction 1 / Quality Improvement Tools 1 / Computer Program 4

2 Lean Enterprise

Objectives 95 Introduction 95 / Continuous and Batch Processes 95 / Multi-Vari Chart 98 / ShortRun SPC 98 / Gauge Control 107 / Computer Program 108

5

Objectives 5 Introduction 5 / Historical Review 5 / Lean Fundamentals 5 / Value Stream Map 8 / Implementing Lean 8 / Benefits to Lean Enterprise 9 / Additional Comments 9

3 Six Sigma

11

Objectives 11 Introduction 11 / Historical Review 11 / Statistical Aspects 11 / Improvement Methodology 13 / Additional Comments 17

4 Statistical Process Control (SPC)

19

Objectives 19 Introduction 19 / Pareto Diagram 19 / Cause-and-Effect Diagram 20 / Check Sheets 22 / Process Flow Diagram 23 / Scatter Diagram 24 / Histogram 24 / Control Charts 25 / Run Chart 26 / Computer Program 26

5 Fundamentals of Statistics

27

Objectives 27 Introduction 27 / Frequency Distribution 30 / Measures of Central Tendency 37 / Measures of Dispersion 40 / Other Measures 42 / Concept of a Population and a Sample 44 / The Normal Curve 45 / Tests for Normality 49 / Scatter Diagram 50 / Computer Program 53

6 Control Charts for Variables

8 Fundamentals of Probability

110

Objectives 110 Introduction 110 / Basic Concepts 110 / Discrete Probability Distributions 115 / Continuous Probability Distributions 119 / Distribution Interrelationship 120 / Computer Program 120

9 Control Charts for Attributes

123

Objectives 123 Introduction 123 / Control Charts for Nonconforming Units 124 / Control Charts for Count of Nonconformities 135 / A Quality Rating System 141 / Computer Program 142

10 Acceptance Sampling

149

Objectives 149 Introduction 149 / Fundamental Concepts 149 / Statistical Aspects 152 / Sampling Plan Design 162 / Sampling Plan Systems 165 / Computer Program 166

11 Reliability

169

Objectives 169 Introduction 169 / Fundamental Aspects 169 / Additional Statistical Aspects 171 / Life and Reliability Testing Plans 176 / Test Design 180 / Availability and Maintainability 181 / Computer Program 181

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Objectives 58 Introduction 58 / Control Chart Techniques 62 / State of Control 72 / Specifications 77 / Process Capability 82 / Other Control Charts 84 / Computer Program 90

12 Management and Planning Tools

184

Objectives 184 Introduction 184 / Why, Why 184 / Forced Field Analysis 184 / Nominal Group Technique 185 / Affinity Diagram 185 / v

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Contents

Interrelationship Diagram 186 / Tree Diagram 187 / Matrix Diagram 187 / Prioritization Matrices 189 / Process Decision Program Chart 190 / Activity Network Diagram 191 / Summary 192

13 Experimental Design

Appendix

237

Table A Areas Under the Normal Curve 237 / Table B Factors for Computing Central Lines and 3s Control Limits for X, s, and R Charts 239 / Table C The Poisson Distribution 240 / Table D Random Numbers 244 / Table E Commonly Used Conversion Factors 245 / Table-F Critical Values, t,m, of t Distribution 245 / Table G-1 Critical Values, F,v1, v2, of F Distribution ( = 0.1) 246 / Table G-2 Critical Values, F,v1, v2, of F Distribution ( = 0.05) 247 / Table G-3 Critical Values, F,v1, v2, of F Distribution ( = 0.01) 248 / Table H Orthogonal Arrays, Interaction Tables, and Linear Graphsa 249

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Objectives 194 Introduction 194 / Basic Statistics 195 / Hypotheses 195 / t Test 196 / F Test 198 / One Factor at a Time 200 / Orthogonal Design 201 / Point and Interval Estimate 202 / Two Factors 202 / Full Factorials 204 / Fractional Factorials 206 / Examples 207 / Conclusion 208 / Computer Program 208

Selected Bibliography

14 Taguchi’s Quality Engineering

211

Objectives 211 Introduction 211 / Loss Function 211 / Orthogonal Arrays 214 / Signal-to-Noise (S/N) Ratio 218 / Parameter Design 219 / Tolerance Design 227 / Conclusion 233

Glossary

255

257

Answers To Selected Exercises Index

263

259

CHAPTER

ONE

INTRODUCTION TO QUALITY IMPROVEMENT

OBJECTIVES Upon completion of this chapter, the reader is expected to .

be able to define quality, quality control, quality improvement, statistical quality control, quality assurance, and process;

.

be able to describe FMEA, QFD, ISO9000, ISO14000, Benchmarking, TPM, Quality by Design, Products Liability, and IT.

INTRODUCTION

Definitions When the term quality is used, we usually think of an excellent product or service that fulfills or exceeds our expectations. These expectations are based on the intended use and the selling price. For example, a customer expects a different performance from a plain steel washer than from a chrome-plated steel washer because they are different grades. When a product surpasses our expectations, we consider that quality. Thus, it is somewhat of an intangible based on perception. Quality can be quantified as follows: Q =

P E

where Q  quality P  performance E  expectations If Q is greater than 1.0, then the customer has a good feeling about the product or service. Of course, the determination of P and E will most likely be based on perception, with the organization determining performance and the customer determining expectations. Customer expectations are continually becoming more demanding. The American Society for Quality (ASQ) defines quality as a subjective term for which each person or sector has its own definition. In technical usage, quality can have two meanings: the characteristics of a product or service that

bear on its ability to satisfy stated or implied needs, or a product or service that is free of deficiencies.1 A more definitive definition of quality is given in ISO 9000. It is defined there as the degree to which a set of inherent characteristics fulfills requirements. Degree means that quality can be used with adjectives such as poor, good, and excellent. Inherent is defined as existing in something, especially as a permanent characteristic. Characteristics can be quantitative or qualitative. Requirement is a need or expectation that is stated; generally implied by the organization, its customers, and other interested parties; or obligatory. Quality control is the use of techniques and activities to achieve and sustain the quality of a product or service. Quality improvement is the use of tools and techniques to continually make the product or service better and better. Statistical quality control (SQC) is the collection, analysis, and interpretation of data for use in quality activities. Quality assurance is all the planned or systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements for quality. It involves making sure that quality is what it should be. This includes a continuing evaluation of adequacy and effectiveness with a view to having timely corrective measures and feedback initiated where necessary. A process is a set of interrelated activities that uses specific inputs to produce specific outputs. The output of one process is usually the input to another. Process refers to both business and production activities. Customer refers to both internal and external customers, and supplier refers to both internal and external suppliers.

QUALITY IMPROVEMENT TOOLS Quality improvement is not the responsibility of any one person or functional area; it is everyone’s job. It includes the equipment operator, the keyboard operator, the purchasing agent, the design engineer, and the president of the company. There are many improvement tools to assist the organization and individuals to improve their product or service. Those 1

Dave Nelson and Susan E. Daniels, “Quality Glossary,” Quality Progress (June 2007): 39–59.

1

CHAPTER ONE

2

provided in this book are check sheets, Pareto diagram, cause and effect diagram, process map, run chart, statistics, control charts, probability, gauge repeatability and reproducibility (GR&R), acceptance sampling, reliability, management and planning tools, experimental design, and Taguchi’s quality engineering. A brief description of those tools not covered follows.

Failure Mode and Effect Analysis (FMEA) FMEA is an analytical technique (a paper test) that combines the technology and experience of people in identifying foreseeable failure modes of a product, service, or process, and planning for its elimination. In other words, FMEA can be explained as a group of activities intended to .

.

.

recognize and evaluate the potential failure of a product, service, or process and its effects; identify actions that could eliminate or reduce the chance of the potential failure occurring; document the process.

FMEA is a before-the-event action requiring a team effort to alleviate most easily and inexpensively changes in design and production. There are two types of FMEA: Design FMEA and Process FMEA.

Quality Function Deployment (QFD) QFD is a system that identifies and sets the priorities for product, service, and process improvement opportunities that lead to increased customer satisfaction. It ensures the accurate deployment of the “voice of the customer” throughout the organization, from product planning to field service. The multifunctional team approach to QFD improves those processes necessary to provide goods and services that meet or exceed customer expectations. The QFD process answers the following questions: 1. What do customers want? 2. Are all wants equally important? 3. Will delivering perceived needs yield a competitive advantage? 4. How can we change the product, service, or process? 5. How does an engineering decision affect customer perception? 6. How does an engineering change affect other technical descriptors? 7. What is the relationship to parts deployment, process planning, and production planning? QFD reduces start-up costs, reduces engineering design changes, and, most important, leads to increased customer satisfaction.

ISO 9000 ISO stands for International Organization for Standards. The 9000 series is a standardized Quality Management

System (QMS) that has been approved by over 100 countries. It consists of three standards: (1) ISO 9000, which covers fundamentals and vocabulary; (2) ISO 9001, which is the requirements; and (3) ISO 9004, which provides guidance for performance improvement. The latest revision of ISO 9000 occurred in the year 2008, hence the designation ISO 9001:8000. The five clauses of QMS are continual improvement; management responsibility; resource management; product/service realization; and measurement, analysis, and improvement. These five clauses are related to customer requirements and customer satisfaction.

ISO 14000 ISO 14000 is the international standard for an environmental management system (EMS). It provides organizations with the EMS elements that can be integrated into other management systems to help achieve environmental and economic goals. The standard describes the requirements for registration and/or self-declaration of the organization’s EMS. Demonstration of successful implementation of the system can be used to assure other parties that an appropriate EMS is in place. ISO 14000 was written to be applicable to all types and sizes of organizations and to accommodate diverse geographic, cultural, and social conditions. The requirements are based on the process and not on the product or service. It does, however, require commitment to the organization’s EMS policy, applicable regulations, and continual improvement. The basic approach to EMS begins with the environmental policy, which is followed by planning, implementation, and operation; checking and corrective action; and management review. There is a logical sequence of events to achieve continual improvement. Many of the requirements may be developed concurrently or revisited at any time. The overall aim is to support environmental protection and prevention of pollution in balance with socioeconomic needs.

Benchmarking It is the search for industry’s best practices that leads to superior performance. Benchmarking is a relatively new way of doing business that was developed by Xerox in 1979. The idea is to find another company that is doing a particular process better than your company and then, using that i...