Design of Experiments With Minitab

Paul G. Mathews

Description

Most of the classic DOE books were written before DOE software was generally available, so the technical level that they assumed was that of the engineer or scientist who had to write his or her own analysis software. In this practical introduction to DOE, guided by the capabilities of the common software packages, Paul Mathews presents the basic types and methods of designed experiments appropriate for engineers, scientists, quality engineers, and Six Sigma Black Belts and Master Black Belts. Although instructions in the use of Minitab are detailed enough to provide effective guidance to a new Minitab user, the book is still general enough to be very helpful to users of other DOE software packages. Every chapter contains many examples with detailed solutions including extensive output from Minitab.

Sujets

• Business
• Qualité, hygiène, sécurité, environnement
• Total Quality Management
• Gestion et management
• Manufacturing
• Engineering
• Economics

Informations

• Publié par: ASQ Quality Press
• Date de parution: 07 juillet 2004
• Nombre de lectures: 0
• EAN13: 9780873895873
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Design of Experiments
with MINITABAlso available from ASQ Quality Press:
Introduction to Design of Experiments: A Simplified Approach
Larry B. Barrentine
Glossary and Tables for Statistical Quality Control, Fourth Edition
ASQ Statistics Division
The Desk Reference of Statistical Quality Methods
Mark L. Crossley
Statistical Quality Control Using Excel, Second Edition
Steven M. Zimmerman, PhD and Marjorie L. Icenogle, PhD
Improving Performance Through Statistical Thinking
ASQ Statistics Division
The Quality Improvement Glossary
Donald L. Siebels
The Metrology Handbook
Jay L. Bucher, editor
Failure Mode and Effect Analysis: FMEA From Theory to Execution, Second Edition
D.H. Stamatis
Concepts for R&R Studies, Second Edition
Larry B. Barrentine
To request a complimentary catalog of ASQ Quality Press publications,
call 800-248-1946, or visit our Web site at http://qualitypress.asq.org.Design of Experiments
with MINITAB
Paul G. Mathews
ASQ Quality Press
Milwaukee, WisconsinAmerican Society for Quality, Quality Press, Milwaukee 53203
© 2005 by ASQ
All rights reserved. Published 2004
Printed in the United States of America
12 11 10 09 08 07 06 05 04 54321
Library of Congress Cataloging-in-Publication Data
Mathews, Paul G., 1960–
Design of experiments with MINITAB / Paul G. Mathews.
p. cm.
Includes bibliographical references and index.
ISBN 0-87389-637-8 (hardcover, case binding : alk. paper)
1. Statistical hypothesis testing. 2. Experimental design. 3. Minitab. 4.
Science—Statistical methods. 5. Engineering—Statistical methods. I. Title.
QA277.M377 2004
519.5'7—dc22 2004020013
ISBN 0-87389-637-8
Copyright Protection Notice for the ANSI/ISO 9000 Series Standards: These materials are subject
to copyright claims of ISO, ANSI, and ASQ. Not for resale. No part of this publication may be
reproduced in any form, including an electronic retrieval system, without the prior written
permission of ASQ. All requests pertaining to the ANSI/ISO 9000 Series Standards should be
submitted to ASQ.
No part of this book may be reproduced in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without the prior written permission of the publisher.
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Printed on acid-free paperTable of Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
Chapter 1 Graphical Presentation of Data . . . . . . . . . . . . . . . . . . 1
1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Types of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Bar Charts 2
1.4 Histograms 3
1.5 Dotplots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 Stem-and-Leaf Plots . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.7 Box-and-Whisker Plots . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.8 Scatter Plots 6
1.9 Multi-Vari Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.10 An Introduction to MINITAB . . . . . . . . . . . . . . . . . . . . . 9
1.10.1 Starting MINITAB . . . . . . . . . . . . . . . . . . . . . . . 9
1.10.2 MINITAB Windows . . . . . . . . . . . . . . . . . . . . . . 9
1.10.3 Using the Command Prompt . . . . . . . . . . . . . . . . . . 11
1.10.4 Customizing MINITAB . . . . . . . . . . . . . . . . . . . . 11
1.10.5 Entering Data . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.10.6 Graphing Data . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.10.7 Printing Data and Graphs . . . . . . . . . . . . . . . . . . . 13
1.10.8 Saving and Retrieving Information . . . . . . . . . . . . . . 14
1.10.9 MINITAB Macros . . . . . . . . . . . . . . . . . . . . . . . 15
1.10.10 Summary of MINITAB Files . . . . . . . . . . . . . . . . . 17
Chapter 2 Descriptive Statistics . . . . . . . . . . . . . . . . . . . . . . . . 19
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2 Selection of Samples . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3 Measures of Location . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.1 The Median . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
vvi Table of Contents
2.3.2 The Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4 Measures of Variation . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.4.1 The Range 21
2.4.2 The Standard Deviation . . . . . . . . . . . . . . . . . . . . . 22
2.4.3 Degrees of Freedom . . . . . . . . . . . . . . . . . . . . . . . 24
2.4.4 The Calculating Form for the Standard Deviation . . . . . . . 25
2.5 The Normal Distribution . . . . . . . . . . . . . . . . . . . . . . . . 26
2.6 Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.6.1 Multiplication of Choices . . . . . . . . . . . . . . . . . . . . 30
2.6.2 Factorials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.6.3 Permutations . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.6.4 Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2.7 MINITAB Commands to Calculate Descriptive Statistics . . . . . . . 34
Chapter 3 Inferential Statistics 37
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2 The Distribution of Sample Means (s Known) . . . . . . . . . . . . 38
3.3 Confidence Interval for the Population Mean (s Known) . . . . . . 41
3.4 Hypothesis Test for One Sample Mean (s Known) . . . . . . . . . . 42
3.4.1 Hypothesis Test Rationale . . . . . . . . . . . . . . . . . . . . 42
3.4.2 Decision Limits Based on Measurement Units . . . . . . . . . 44
3.4.3 Decision Limits Based on Standard (z) Units 45
3.4.4 Decision Limits Based on the p Value . . . . . . . . . . . . . 46
3.4.5 Type 1 and Type 2 Errors 49
3.4.6 One-Tailed Hypothesis Tests . . . . . . . . . . . . . . . . . . 51
3.5 The Distribution of Sample Means (s Unknown) . . . . . . . . . . 52
3.5.1 Student’s t Distribution . . . . . . . . . . . . . . . . . . . . . 52
3.5.2 A One-Sample Hypothesis Test for the Population Mean
(s Unknown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
3.5.3 A Confidence Interval for the Population Mean
(s Unknown) 55
3.6 Hypothesis Tests for Two Means . . . . . . . . . . . . . . . . . . . . 56
2 23.6.1 Two Independent Samples (s and s Known) . . . . . . . . 561 2
2 23.6.2 Tws and s Unknown 1 2
But Equal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2 23.6.3 Tws and s Unknown 1 2
and Unequal) 58
3.6.4 Paired Samples . . . . . . . . . . . . . . . . . . . . . . . . . . 59
3.7 Inferences About One Variance (Optional) . . . . . . . . . . . . . . 61
3.7.1 The Distribution of Sample Variances 61
3.7.2 Hypothesis Test for One Sample Variance . . . . . . . . . . . 63
3.7.3 Confidence Interval for the Population Variance . . . . . . . . 64
3.8 Hypothesis Tests for Two Sample Variances 65
3.9 Quick Tests for the Two-Sample Location Problem . . . . . . . . . . 68Table of Contents vii
3.9.1 Tukey’s Quick Test . . . . . . . . . . . . . . . . . . . . . . . 69
3.9.2 Boxplot Slippage Tests . . . . . . . . . . . . . . . . . . . . . 71
3.10 General Procedure for Hypothesis Testing . . . . . . . . . . . . . . 73
3.11 Testing for Normality . . . . . . . . . . . . . . . . . . . . . . . . . 75
3.11.1 Normal Probability Plots . . . . . . . . . . . . . . . . . . . . 75
3.11.2 Quantitative Tests for Normality . . . . . . . . . . . . . . . . 78
3.12 Hypothesis Tests and Confidence Intervals with MINITAB . . . . . 79
3.12.1 Confidence Interval for m When s is Known . . . . . . . . . 79
3.12.2 Hypothesis Tests for One Sample Mean (s Known) . . . . . 80
3.12.3 Normal Probability Plots with MINITAB . . . . . . . . . . . 82
3.13 Sample-Size Calculations . . . . . . . . . . . . . . . . . . . . . . . 82
3.13.1 Sample-Size Calculations for Confidence Intervals . . . . . . 83
3.13.2for Hypothesis Tests . . . . . . . . 86
Chapter 4 DOE Language and Concepts . . . . . . . . . . . . . . . . . . . 93
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
4.2 Design of Experiments: Definition, Scope, and Motivation . . . . . . 93
4.3 Experiment Defined . . . . . . . . . . . . . . . . . . . . . . . . . . 94
4.4 Identification of Variables and Responses . . . . . . . . . . . . . . . 94
4.5 Types of Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4.6 Types of Responses 97
4.7 Interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
4.8 Types of Experiments . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.9 Types of Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
4.10 Selection of Variable Levels . . . . . . . . . . . . . . . . . . . . . 105
4.10.1 Qualitative Variable Levels . . . . . . . . . . . . . . . . . . . 105
4.10.2 Quantitative Variable Levels . . . . . . . . . . . . . . . . . . 105
4.11 Nested Variables 106
4.12 Covariates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
4.13 Definition of Design in Design of