Measuring the software process: statistical process control for software process improvement

273 Pages·1999·2.463 MB·English

by  Carleton, Anita D., Florac, William A

Measuring the
Software Process
Statistical Process Control for
Software Process Improvement
William A. Florac
Anita D. Carleton
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ADDISON-WESLEY
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Software Engineering Institute
The SEI Series in Software Engineering
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Special permission to use Practical Software Measuremnet: Measuring for Process Management and
Improvement, CMU/SEI-97-HB-003, and Goal-Driven Software Measurement—A Guidebook, CMU/
SEI-96-HB-002, by Carnegie Mellon University, in Measuring the Software Process: Statistical Pro-
cess Control for Software Process Improvement, is granted by the Software Engineering Institute.
PSP and Personal Software Process are service marks of Carnegie Mellon University. Additional
copyright information appears on page 250.
Library of Congress Cataloging-in-Publication Data
Florac, William A.
Measuring the software process : statistical process control for
software process improvement / William A. Florac, Anita D. Carleton.
p. cm. -- (The SEI series in software engineering)
Includes bibliographical references.
ISBN 0-201-60444-2
1. Software measurement. 2. Computer software--Quality control-
-Statistical methods. I. Carleton, Anita D. II. Title.
III. Series.
QA76.76.S65F56 1999
005.1'4--dc21 99-20519
CIP
Copyright ©1999 by Pearson Education.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form, or by any means, electronic, mechanical, photo-copying, recording, or other-
wise, without the prior consent of the publisher. Printed in the United States of America.
ISBN 0-201-60444-2
Text printed in the United States on recycled paper at Courier in Westford, Massachusetts.
7th Printing, May 2008
To Marilyn, my wife and best friend for over fifty years.
—Bill
I dedicate this book to my Denny, Neil, Kellen, and my parents—
the source of all of my inspiration and support for everything I do.
—Anita
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Contents
Figures ix
Foreword xv
Preface xvii
Acknowledgments xxi
CHAPTER 1 Managing and Measuring Process Behavior 1
1.1 What Is a Software Process? 3
1.2 What Is Software Process Management? 4
1.3 The Role of Software Process
Management 5
1.4 Issues on the Road to Process
Improvement 8
1.5 The Need for Software Process
Measurement 10
1.6 Measuring Process Behavior 11
1.7 A Framework for Process Behavior
Measurement 14
1.8 Summary 15
CHAPTER 2 Planning for Measurement 17
2.1 Identifying Process Issues 17
2.2 Selecting and Defining Measures 23
2.3 Integrating Measures with the Software
Process 35
2.4 Summary 40
CHAPTER 3 Collecting the Data 43
3.1 Principal Tasks 43
3.2 The Specifics of Collecting Software
Process Data 45
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vi Contents
3.3 Reviewing and Assessing Collected Data 49
3.4 Retaining Data 52
3.5 Tools for Understanding Your Data 54
3.6 Summary 64
CHAPTER 4 Analyzing Process Behavior 65
4.1 Separating Signals from Noise 66
4.2 Evaluating Process Stability 70
4.3 Control Chart Basics 76
4.4 Summary 84
CHAPTER 5 Process Behavior Charts for Software
Processes 85
5.1 Control Charts for Variables or
Discrete Data 85
5.2 Control Charts for Attributes Data 109
5.3 Summary 123
CHAPTER 6 More About Process Behavior Charts 125
6.1 How Much Data Is Enough? 125
6.2 Anomalous Process Behavior Patterns 131
6.3 Rational Sampling and Homogeneity of
Subgroups 136
6.4 Rational Subgrouping 137
6.5 The Problem of Insufficient Granularity in
Recorded Values 146
6.6 Aggregation and Decomposition of Process
Performance Data 149
6.7 Summary 152
CHAPTER 7 Three Paths to Process Improvement 155
7.1 Finding and Correcting Assignable Causes 157
7.2 Process Capability 176
7.3 Process Capability Analysis 179
7.4 Improving the Process 186
7.5 Improvement and Investment 198
7.6 Summary 201
Contents vii
CHAPTER 8 Getting Started 205
8.1 Ten Steps for Getting Started 205
8.2 Frequently Asked Questions Regarding
SPC 207
8.3 Final Remarks 214
APPENDIX A Control Chart Tables and Formulas 215
APPENDIX B More About Analyzing Process Behavior 221
B.1 Enumerative Versus Analytic Studies 221
B.2 Three-Sigma Control Limits 227
B.3 Central Limit Theorem and Role of the
Normal Distribution 230
APPENDIX C Example Data and Calculations 233
Appendix C.1 233
Appendix C.2 234
References 237
Index 243
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Figures
Figure 1.1 Definition ofProcess 4
Figure 1.2 The Four Key Responsibilities of Process Management 6
Figure 1.3 Business Goals, Project and Process Issues, and Related
Measurable Attributes 13
Figure 1.4 Book Organization in Context of Process Behavior
Measurement Framework 15
Figure 2.1 Process Measurement Framework Guide to Chapter 2 18
Figure 2.2 The Three Principal Activities of Measurement Planning 18
Figure 2.3 A Generic Process Model 20
Figure 2.4 A Simple Process Model for Defect Tracking 21
Figure 2.5 Example of a Control-Flow Diagram 22
Figure 2.6 Measurement Planning Activities—Step 2 24
Figure 2.7 Guidelines for Selecting Process Performance Measures 25
Figure 2.8 Examples of Measurable Entities in a Software Process 27
Figure 2.9 Examples of Measurable Attributes Associated with
Software Process Entities 28
Figure 2.10 A Checklist-Based Definition for Counting Defects 33
Figure 2.11 Measurement Planning Activities—Step 3 35
Figure 2.12 Sources for Problem-Tracking Data 36
Figure 2.13 Checklist for Preparing a Measurement Action Plan 38
Figure 2.14 Status of Action-Planning Activities 39
Figure 2.15 Example of Factors to Consider for Measurement
Evaluation 41
Figure 3.1 Process Measurement Framework Guide to Chapter 3 44
Figure 3.2 The Personal Software Process 47
Figure 3.3 PSP Measures and Definitions 48
Figure 3.4 Application Areas for Analytic Tools 55
Figure 3.5 Example of a Scatter Diagram 56
Figure 3.6 Example of a Run Chart with Level Performance 57
Figure 3.7 Example of a Run Chart with a Rising Trend 57
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