7th_ed_software_engineering_a_practitioners_approach_by_roger_s._pressman_.pdf

Praise for earlier editions of Seventh Software Engineering: A Practitioner’s Approach...

Praise for earlier editions of Seventh Software Engineering: A Practitioner’s Approach Edition “Roger Pressman has written a solid comprehensive guidebook for the field of software engineering for both students of the discipline and software developers and managers practicing it—or needing to practice it.” IEEE Software “This is a classic modern textbook, clear and authoritative, with lots of pictures, examples, questions and references.... I recommend it to anyone who asks, ‘What is software engineering and where is it now?’ ACM Computing Reviews Roger S. Pressman, Ph.D Software Engineering Software Engineering “An up-to-the minute, in-depth treatment of the software engineering process.” Byte Book Club (main selection) “... had the best explanations of what I want to cover...” A Practitioner’s Approach A Practitioner’s Approach “... The definitive book on the subject as far as I’m concerned...” “... A good textbook as well as reference...” from comp.software-eng FAQ “As a practicing Software Engineer, I find this book to be invaluable. It has served as a great reference for all the projects that I have worked on.” Seventh Edition “This book is a framework on how to develop high quality software.” reviews from Amazon.com For almost three decades, Software Engineering: A Practitioner’s Approach has been the best selling guide to software engineering for students and industry professionals alike. In its seventh edition, the book has been restructured and redesigned, undergoing a substantial content update that addresses every important topic in what many have called “the engineering discipline of the 21st century.” Unique sidebars and marginal content have been expanded and enhanced, offering the reader an entertaining and informative complement to chapter topics. New chapters and a new organization make the book still easier MD DALIM #1001702 12/23/08 CYAN MAG YELO BLK to use in the classroom and as a self-study guide. Part 1, The Software Process, presents both prescriptive and agile process models. Part 2, Modeling, presents modern analysis and design methods with a new emphasis on UML-based modeling. Part 3, Quality Management, is new for the seventh edition and address all aspects of software testing, quality assurance, formal verification techniques, and change management. Part 4, Managing Software Projects, presents topics that are relevant to those who plan, manage, and control a software project. Part 5, Advanced Topics, presents dedicated chapters that address software process improvement and future software engineering trends. Roger Pressman, continuing in the tradition of his earlier editions, has written a book that will serve as an excellent guide to software engineering for everyone who must understand, build, or manage computer-based systems. Visit the book’s On-Line Learning Center at www.mhhe.com/pressman. The site, visited by thousands of readers each month, has been significantly expanded and updated to provide comprehensive software engineering resources for students, instructors, and industry professionals. Pressman Roger S. Pressman pre75977_FM.qxd 11/27/08 6:38 PM Page i Software Engineering A PRACTITIONER’S APPROACH pre75977_FM.qxd 11/27/08 6:38 PM Page ii pre75977_FM.qxd 11/27/08 6:38 PM Page iii Software Engineering A PRACTITIONER’S APPROACH SEVENTH EDITION Roger S. Pressman, Ph.D. pre75977_FM.qxd 11/27/08 6:38 PM Page iv SOFTWARE ENGINEERING: A PRACTITIONER’S APPROACH, SEVENTH EDITION Published by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2010 by The McGraw-Hill Companies, Inc. All rights reserved. Previous editions © 2005, 2001, and 1997. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. Some ancillaries, including electronic and print components, may not be available to customers outside the United States. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 DOC/DOC 0 9 ISBN 978–0–07–337597–7 MHID 0–07–337597–7 Global Publisher: Raghothaman Srinivasan Director of Development: Kristine Tibbetts Senior Marketing Manager: Curt Reynolds Senior Managing Editor: Faye M. Schilling Lead Production Supervisor: Sandy Ludovissy Senior Media Project Manager: Sandra M. Schnee Associate Design Coordinator: Brenda A. Rolwes Cover Designer: Studio Montage, St. Louis, Missouri (USE) Cover Image: © The Studio Dog/Getty Images Compositor: Macmillan Publishing Solutions Typeface: 8.5/13.5 Leawood Printer: R. R. Donnelley Crawfordsville, IN Library of Congress Cataloging-in-Publication Data Pressman, Roger S. Software engineering : a practitioner’s approach / Roger S. Pressman. — 7th ed. p. cm. Includes index. ISBN 978–0–07–337597–7 — ISBN 0–07–337597–7 (hard copy : alk. paper) 1. Software engineering. I. Title. QA76.758.P75 2010 005.1—dc22 2008048802 www.mhhe.com pre75977_FM.qxd 11/27/08 6:38 PM Page v In loving memory of my father who lived 94 years and taught me, above all, that honesty and integrity were the best guides for my journey through life. pre75977_FM.qxd 11/27/08 6:38 PM Page vi A BOUT THE A UTHOR oger S. Pressman is an internationally recognized authority in software process R improvement and software engineering technologies. For almost four decades, he has worked as a software engineer, a manager, a professor, an author, and a con- sultant, focusing on software engineering issues. As an industry practitioner and manager, Dr. Pressman worked on the development of CAD/CAM systems for advanced engineering and manufacturing applications. He has also held positions with responsibility for scientific and systems programming. After receiving a Ph.D. in engineering from the University of Connecticut, Dr. Pressman moved to academia where he became Bullard Associate Professor of Computer Engineering at the University of Bridgeport and director of the university’s Computer-Aided Design and Manufacturing Center. Dr. Pressman is currently president of R.S. Pressman & Associates, Inc., a consulting firm specializing in software engineering methods and training. He serves as principal consultant and has designed and developed Essential Software Engineering, a complete video curriculum in software engineering, and Process Advisor, a self-directed system for software process improvement. Both products are used by thousands of companies worldwide. More recently, he has worked in collaboration with EdistaLearning in India to develop comprehensive Internet-based training in software engineering. Dr. Pressman has written many technical papers, is a regular contributor to industry periodicals, and is author of seven technical books. In addition to Software Engineering: A Practitioner’s Approach, he has co-authored Web Engineering (McGraw-Hill), one of the first books to apply a tailored set of software engineering principles and practices to the development of Web-based systems and applications. He has also written the award-winning A Manager’s Guide to Software Engineering (McGraw-Hill); Making Software Engineering Happen (Prentice Hall), the first book to address the critical management problems associated with software process improvement; and Software Shock (Dorset House), a treatment that focuses on soft- ware and its impact on business and society. Dr. Pressman has been on the editorial boards of a number of industry journals, and for many years, was editor of the “Manager” column in IEEE Software. Dr. Pressman is a well-known speaker, keynoting a number of major industry conferences. He is a member of the IEEE, and Tau Beta Pi, Phi Kappa Phi, Eta Kappa Nu, and Pi Tau Sigma. On the personal side, Dr. Pressman lives in South Florida with his wife, Barbara. An athlete for most of his life, he remains a serious tennis player (NTRP 4.5) and a single-digit handicap golfer. In his spare time, he has written two novels, The Aymara Bridge and The Puppeteer, and plans to begin work on another. vi pre75977_FM.qxd 11/27/08 6:38 PM Page vii C ONTENTS AT A G LANCE CHAPTER 1 Software and Software Engineering 1 PAR T ONE THE SOFTWARE PROCESS 29 CHAPTER 2 Process Models 30 CHAPTER 3 Agile Development 65 PAR T TWO MODELING 95 CHAPTER 4 Principles that Guide Practice 96 CHAPTER 5 Understanding Requirements 119 CHAPTER 6 Requirements Modeling: Scenarios, Information, and Analysis Classes 148 CHAPTER 7 Requirements Modeling: Flow, Behavior, Patterns, and WebApps 186 CHAPTER 8 Design Concepts 215 CHAPTER 9 Architectural Design 242 CHAPTER 10 Component-Level Design 276 CHAPTER 11 User Interface Design 312 CHAPTER 12 Pattern-Based Design 347 CHAPTER 13 WebApp Design 373 PAR T THREE QUALITY MANAGEMENT 397 CHAPTER 14 Quality Concepts 398 CHAPTER 15 Review Techniques 416 CHAPTER 16 Software Quality Assurance 432 CHAPTER 17 Software Testing Strategies 449 CHAPTER 18 Testing Conventional Applications 481 CHAPTER 19 Testing Object-Oriented Applications 511 CHAPTER 20 Testing Web Applications 529 CHAPTER 21 Formal Modeling and Verification 557 CHAPTER 22 Software Configuration Management 584 CHAPTER 23 Product Metrics 613 PAR T FOUR MANAGING SOFTWARE PROJECTS 645 CHAPTER 24 Project Management Concepts 646 CHAPTER 25 Process and Project Metrics 666 vii pre75977_FM.qxd 11/27/08 6:38 PM Page viii viii PART TWO CONTENTS AT A GLANCE CHAPTER 26 Estimation for Software Projects 691 CHAPTER 27 Project Scheduling 721 CHAPTER 28 Risk Management 744 CHAPTER 29 Maintenance and Reengineering 761 PAR T FIVE ADVANCED TOPICS 785 CHAPTER 30 Software Process Improvement 786 CHAPTER 31 Emerging Trends in Software Engineering 808 CHAPTER 32 Concluding Comments 833 APPENDIX 1 An Introduction to UML 841 APPENDIX 2 Object-Oriented Concepts 863 REFERENCES 871 INDEX 889 pre75977_FM.qxd 11/27/08 6:38 PM Page ix TABLE OF C ONTENTS Preface xxv CHAPTER 1 SOFTWARE AND SOFTWARE ENGINEERING 1 1.1 The Nature of Software 3 1.1.1 Defining Software 4 1.1.2 Software Application Domains 7 1.1.3 Legacy Software 9 1.2 The Unique Nature of WebApps 10 1.3 Software Engineering 12 1.4 The Software Process 14 1.5 Software Engineering Practice 17 1.5.1 The Essence of Practice 17 1.5.2 General Principles 19 1.6 Software Myths 21 1.7 How It All Starts 24 1.8 Summary 25 PROBLEMS AND POINTS TO PONDER 25 FURTHER READINGS AND INFORMATION SOURCES 26 PAR T ONE THE SOFTWARE PROCESS 29 CHAPTER 2 PROCESS MODELS 30 2.1 A Generic Process Model 31 2.1.1 Defining a Framework Activity 32 2.1.2 Identifying a Task Set 34 2.1.3 Process Patterns 35 2.2 Process Assessment and Improvement 37 2.3 Prescriptive Process Models 38 2.3.1 The Waterfall Model 39 2.3.2 Incremental Process Models 41 2.3.3 Evolutionary Process Models 42 2.3.4 Concurrent Models 48 2.3.5 A Final Word on Evolutionary Processes 49 2.4 Specialized Process Models 50 2.4.1 Component-Based Development 50 2.4.2 The Formal Methods Model 51 2.4.3 Aspect-Oriented Software Development 52 2.5 The Unified Process 53 2.5.1 A Brief History 54 2.5.2 Phases of the Unified Process 54 2.6 Personal and Team Process Models 56 2.6.1 Personal Software Process (PSP) 57 2.6.2 Team Software Process (TSP) 58 2.7 Process Technology 59 2.8 Product and Process 60 ix pre75977_FM.qxd 11/27/08 6:38 PM Page x x TABLE OF CONTENTS 2.9 Summary 61 PROBLEMS AND POINTS TO PONDER 62 FURTHER READINGS AND INFORMATION SOURCES 63 CHAPTER 3 AGILE DEVELOPMENT 65 3.1 What Is Agility? 67 3.2 Agility and the Cost of Change 67 3.3 What Is an Agile Process? 68 3.3.1 Agility Principles 69 3.3.2 The Politics of Agile Development 70 3.3.3 Human Factors 71 3.4 Extreme Programming (XP) 72 3.4.1 XP Values 72 3.4.2 The XP Process 73 3.4.3 Industrial XP 77 3.4.4 The XP Debate 78 3.5 Other Agile Process Models 80 3.5.1 Adaptive Software Development (ASD) 81 3.5.2 Scrum 82 3.5.3 Dynamic Systems Development Method (DSDM) 84 3.5.4 Crystal 85 3.5.5 Feature Driven Development (FDD) 86 3.5.6 Lean Software Development (LSD) 87 3.5.7 Agile Modeling (AM) 88 3.5.8 Agile Unified Process (AUP) 89 3.6 A Tool Set for the Agile Process 91 3.7 Summary 91 PROBLEMS AND POINTS TO PONDER 92 FURTHER READINGS AND INFORMATION SOURCES 93 PAR T TWO MODELING 95 CHAPTER 4 PRINCIPLES THAT GUIDE PRACTICE 96 4.1 Software Engineering Knowledge 97 4.2 Core Principles 98 4.2.1 Principles That Guide Process 98 4.2.2 Principles That Guide Practice 99 4.3 Principles That Guide Each Framework Activity 101 4.3.1 Communication Principles 101 4.3.2 Planning Principles 103 4.3.3 Modeling Principles 105 4.3.4 Construction Principles 111 4.3.5 Deployment Principles 113 4.4 Summary 115 PROBLEMS AND POINTS TO PONDER 116 FURTHER READINGS AND INFORMATION SOURCES 116 CHAPTER 5 UNDERSTANDING REQUIREMENTS 119 5.1 Requirements Engineering 120 5.2 Establishing the Groundwork 125 5.2.1 Identifying Stakeholders 125 pre75977_FM.qxd 11/27/08 6:38 PM Page xi TABLE OF CONTENTS xi 5.2.2 Recognizing Multiple Viewpoints 126 5.2.3 Working toward Collaboration 126 5.2.4 Asking the First Questions 127 5.3 Eliciting Requirements 128 5.3.1 Collaborative Requirements Gathering 128 5.3.2 Quality Function Deployment 131 5.3.3 Usage Scenarios 132 5.3.4 Elicitation Work Products 133 5.4 Developing Use Cases 133 5.5 Building the Requirements Model 138 5.5.1 Elements of the Requirements Model 139 5.5.2 Analysis Patterns 142 5.6 Negotiating Requirements 142 5.7 Validating Requirements 144 5.8 Summary 145 PROBLEMS AND POINTS TO PONDER 145 FURTHER READINGS AND INFORMATION SOURCES 146 CHAPTER 6 REQUIREMENTS MODELING: SCENARIOS, INFORMATION, AND ANALYSIS CLASSES 148 6.1 Requirements Analysis 149 6.1.1 Overall Objectives and Philosophy 150 6.1.2 Analysis Rules of Thumb 151 6.1.3 Domain Analysis 151 6.1.4 Requirements Modeling Approaches 153 6.2 Scenario-Based Modeling 154 6.2.1 Creating a Preliminary Use Case 155 6.2.2 Refining a Preliminary Use Case 158 6.2.3 Writing a Formal Use Case 159 6.3 UML Models That Supplement the Use Case 161 6.3.1 Developing an Activity Diagram 161 6.3.2 Swimlane Diagrams 162 6.4 Data Modeling Concepts 164 6.4.1 Data Objects 164 6.4.2 Data Attributes 164 6.4.3 Relationships 165 6.5 Class-Based Modeling 167 6.5.1 Identifying Analysis Classes 167 6.5.2 Specifying Attributes 171 6.5.3 Defining Operations 171 6.5.4 Class-Responsibility-Collaborator (CRC) Modeling 173 6.5.5 Associations and Dependencies 180 6.5.6 Analysis Packages 182 6.6 Summary 183 PROBLEMS AND POINTS TO PONDER 183 FURTHER READINGS AND INFORMATION SOURCES 184 CHAPTER 7 REQUIREMENTS MODELING: FLOW, BEHAVIOR, PATTERNS, AND WEBAPPS 186 7.1 Requirements Modeling Strategies 186 7.2 Flow-Oriented Modeling 187 pre75977_FM.qxd 11/27/08 6:38 PM Page xii xii TABLE OF CONTENTS 7.2.1 Creating a Data Flow Model 188 7.2.2 Creating a Control Flow Model 191 7.2.3 The Control Specification 191 7.2.4 The Process Specification 192 7.3 Creating a Behavioral Model 195 7.3.1 Identifying Events with the Use Case 195 7.3.2 State Representations 196 7.4 Patterns for Requirements Modeling 199 7.4.1 Discovering Analysis Patterns 200 7.4.2 A Requirements Pattern Example: Actuator-Sensor 200 7.5 Requirements Modeling for WebApps 205 7.5.1 How Much Analysis Is Enough? 205 7.5.2 Requirements Modeling Input 206 7.5.3 Requirements Modeling Output 207 7.5.4 Content Model for WebApps 207 7.5.5 Interaction Model for WebApps 209 7.5.6 Functional Model for WebApps 210 7.5.7 Configuration Models for WebApps 211 7.5.8 Navigation Modeling 212 7.6 Summary 213 PROBLEMS AND POINTS TO PONDER 213 FURTHER READINGS AND INFORMATION SOURCES 214 CHAPTER 8 DESIGN CONCEPTS 215 8.1 Design within the Context of Software Engineering 216 8.2 The Design Process 219 8.2.1 Software Quality Guidelines and Attributes 219 8.2.2 The Evolution of Software Design 221 8.3 Design Concepts 222 8.3.1 Abstraction 223 8.3.2 Architecture 223 8.3.3 Patterns 224 8.3.4 Separation of Concerns 225 8.3.5 Modularity 225 8.3.6 Information Hiding 226 8.3.7 Functional Independence 227 8.3.8 Refinement 228 8.3.9 Aspects 228 8.3.10 Refactoring 229 8.3.11 Object-Oriented Design Concepts 230 8.3.12 Design Classes 230 8.4 The Design Model 233 8.4.1 Data Design Elements 234 8.4.2 Architectural Design Elements 234 8.4.3 Interface Design Elements 235 8.4.4 Component-Level Design Elements 237 8.4.5 Deployment-Level Design Elements 237 8.5 Summary 239 PROBLEMS AND POINTS TO PONDER 240 FURTHER READINGS AND INFORMATION SOURCES 240 pre75977_FM.qxd 11/27/08 6:38 PM Page xiii TABLE OF CONTENTS xiii CHAPTER 9 ARCHITECTURAL DESIGN 242 9.1 Software Architecture 243 9.1.1 What Is Architecture? 243 9.1.2 Why Is Architecture Important? 245 9.1.3 Architectural Descriptions 245 9.1.4 Architectural Decisions 246 9.2 Architectural Genres 246 9.3 Architectural Styles 249 9.3.1 A Brief Taxonomy of Architectural Styles 250 9.3.2 Architectural Patterns 253 9.3.3 Organization and Refinement 255 9.4 Architectural Design 255 9.4.1 Representing the System in Context 256 9.4.2 Defining Archetypes 257 9.4.3 Refining the Architecture into Components 258 9.4.4 Describing Instantiations of the System 260 9.5 Assessing Alternative Architectural Designs 261 9.5.1 An Architecture Trade-Off Analysis Method 262 9.5.2 Architectural Complexity 263 9.5.3 Architectural Description Languages 264 9.6 Architectural Mapping Using Data Flow 265 9.6.1 Transform Mapping 265 9.6.2 Refining the Architectural Design 272 9.7 Summary 273 PROBLEMS AND POINTS TO PONDER 274 FURTHER READINGS AND INFORMATION SOURCES 274 CHAPTER 10 COMPONENT-LEVEL DESIGN 276 10.1 What Is a Component? 277 10.1.1 An Object-Oriented View 277 10.1.2 The Traditional View 279 10.1.3 A Process-Related View 281 10.2 Designing Class-Based Components 282 10.2.1 Basic Design Principles 282 10.2.2 Component-Level Design Guidelines 285 10.2.3 Cohesion 286 10.2.4 Coupling 288 10.3 Conducting Component-Level Design 290 10.4 Component-Level Design for WebApps 296 10.4.1 Content Design at the Component Level 297 10.4.2 Functional Design at the Component Level 297 10.5 Designing Traditional Components 298 10.5.1 Graphical Design Notation 299 10.5.2 Tabular Design Notation 300 10.5.3 Program Design Language 301 10.6 Component-Based Development 303 10.6.1 Domain Engineering 303 10.6.2 Component Qualification, Adaptation, and Composition 304 10.6.3 Analysis and Design for Reuse 306 10.6.4 Classifying and Retrieving Components 307 pre75977_FM.qxd 11/27/08 6:38 PM Page xiv xiv TABLE OF CONTENTS 10.7 Summary 309 PROBLEMS AND POINTS TO PONDER 310 FURTHER READINGS AND INFORMATION SOURCES 311 CHAPTER 11 USER INTERFACE DESIGN 312 11.1 The Golden Rules 313 11.1.1 Place the User in Control 313 11.1.2 Reduce the User’s Memory Load 314 11.1.3 Make the Interface Consistent 316 11.2 User Interface Analysis and Design 317 11.2.1 Interface Analysis and Design Models 317 11.2.2 The Process 319 11.3 Interface Analysis 320 11.3.1 User Analysis 321 11.3.2 Task Analysis and Modeling 322 11.3.3 Analysis of Display Content 327 11.3.4 Analysis of the Work Environment 328 11.4 Interface Design Steps 328 11.4.1 Applying Interface Design Steps 329 11.4.2 User Interface Design Patterns 330 11.4.3 Design Issues 331 11.5 WebApp Interface Design 335 11.5.1 Interface Design Principles and Guidelines 336 11.5.2 Interface Design Workflow for WebApps 340 11.6 Design Evaluation 342 11.7 Summary 344 PROBLEMS AND POINTS TO PONDER 345 FURTHER READINGS AND INFORMATION SOURCES 346 CHAPTER 12 PATTERN-BASED DESIGN 347 12.1 Design Patterns 348 12.1.1 Kinds of Patterns 349 12.1.2 Frameworks 352 12.1.3 Describing a Pattern 352 12.1.4 Pattern Languages and Repositories 353 12.2 Pattern-Based Software Design 354 12.2.1 Pattern-Based Design in Context 354 12.2.2 Thinking in Patterns 356 12.2.3 Design Tasks 357 12.2.4 Building a Pattern-Organizing Table 358 12.2.5 Common Design Mistakes 359 12.3 Architectural Patterns 360 12.4 Component-Level Design Patterns 362 12.5 User Interface Design Patterns 364 12.6 WebApp Design Patterns 368 12.6.1 Design Focus 368 12.6.2 Design Granularity 369 12.7 Summary 370 PROBLEMS AND POINTS TO PONDER 371 FURTHER READING AND INFORMATION SOURCES 372 pre75977_FM.qxd 11/27/08 6:38 PM Page xv TABLE OF CONTENTS xv CHAPTER 13 WEBAPP DESIGN 373 13.1 WebApp Design Quality 374 13.2 Design Goals 377 13.3 A Design Pyramid for WebApps 378 13.4 WebApp Interface Design 378 13.5 Aesthetic Design 380 13.5.1 Layout Issues 380 13.5.2 Graphic Design Issues 381 13.6 Content Design 382 13.6.1 Content Objects 382 13.6.2 Content Design Issues 382 13.7 Architecture Design 383 13.7.1 Content Architecture 384 13.7.2 WebApp Architecture 386 13.8 Navigation Design 388 13.8.1 Navigation Semantics 388 13.8.2 Navigation Syntax 389 13.9 Component-Level Design 390 13.10 Object-Oriented Hypermedia Design Method (OOHDM) 390 13.10.1 Conceptual Design for OOHDM 391 13.10.2 Navigational Design for OOHDM 391 13.10.3 Abstract Interface Design and Implementation 392 13.11 Summary 393 PROBLEMS AND POINTS TO PONDER 394 FURTHER READINGS AND INFORMATION SOURCES 395 PAR T THREE QUALITY MANAGEMENT 397 CHAPTER 14 QUALITY CONCEPTS 398 14.1 What Is Quality? 399 14.2 Software Quality 400 14.2.1 Garvin’s Quality Dimensions 401 14.2.2 McCall’s Quality Factors 402 14.2.3 ISO 9126 Quality Factors 403 14.2.4 Targeted Quality Factors 404 14.2.5 The Transition to a Quantitative View 405 14.3 The Software Quality Dilemma 406 14.3.1 “Good Enough” Software 406 14.3.2 The Cost of Quality 407 14.3.3 Risks 409 14.3.4 Negligence and Liability 410 14.3.5 Quality and Security 410 14.3.6 The Impact of Management Actions 411 14.4 Achieving Software Quality 412 14.4.1 Software Engineering Methods 412 14.4.2 Project Management Techniques 412 14.4.3 Quality Control 412 14.4.4 Quality Assurance 413 14.5 Summary 413 PROBLEMS AND POINTS TO PONDER 414 FURTHER READINGS AND INFORMATION SOURCES 414 pre75977_FM.qxd 11/27/08 6:38 PM Page xvi xvi TABLE OF CONTENTS CHAPTER 15 REVIEW TECHNIQUES 416 15.1 Cost Impact of Software Defects 417 15.2 Defect Amplification and Removal 418 15.3 Review Metrics and Their Use 420 15.3.1 Analyzing Metrics 420 15.3.2 Cost Effectiveness of Reviews 421 15.4 Reviews: A Formality Spectrum 423 15.5 Informal Reviews 424 15.6 Formal Technical Reviews 426 15.6.1 The Review Meeting 426 15.6.2 Review Reporting and Record Keeping 427 15.6.3 Review Guidelines 427 15.6.4 Sample-Driven Reviews 429 15.7 Summary 430 PROBLEMS AND POINTS TO PONDER 431 FURTHER READINGS AND INFORMATION SOURCES 431 CHAPTER 16 SOFTWARE QUALITY ASSURANCE 432 16.1 Background Issues 433 16.2 Elements of Software Quality Assurance 434 16.3 SQA Tasks, Goals, and Metrics 436 16.3.1 SQA Tasks 436 16.3.2 Goals, Attributes, and Metrics 437 16.4 Formal Approaches to SQA 438 16.5 Statistical Software Quality Assurance 439 16.5.1 A Generic Example 439 16.5.2 Six Sigma for Software Engineering 441 16.6 Software Reliability 442 16.6.1 Measures of Reliability and Availability 442 16.6.2 Software Safety 443 16.7 The ISO 9000 Quality Standards 444 16.8 The SQA Plan 445 16.9 Summary 446 PROBLEMS AND POINTS TO PONDER 447 FURTHER READINGS AND INFORMATION SOURCES 447 CHAPTER 17 SOFTWARE TESTING STRATEGIES 449 17.1 A Strategic Approach to Software Testing 450 17.1.1 Verification and Validation 450 17.1.2 Organizing for Software Testing 451 17.1.3 Software Testing Strategy—The Big Picture 452 17.1.4 Criteria for Completion of Testing 455 17.2 Strategic Issues 455 17.3 Test Strategies for Conventional Software 456 17.3.1 Unit Testing 456 17.3.2 Integration Testing 459 17.4 Test Strategies for Object-Oriented Software 465 17.4.1 Unit Testing in the OO Context 466 17.4.2 Integration Testing in the OO Context 466 17.5 Test Strategies for WebApps 467 17.6 Validation Testing 467 pre75977_FM.qxd 12/1/08 3:15 PM Page xvii TABLE OF CONTENTS xvii 17.6.1 Validation-Test Criteria 468 17.6.2 Configuration Review 468 17.6.3 Alpha and Beta Testing 468 17.7 System Testing 470 17.7.1 Recovery Testing 470 17.7.2 Security Testing 470 17.7.3 Stress Testing 471 17.7.4 Performance Testing 471 17.7.5 Deployment Testing 472 17.8 The Art of Debugging 473 17.8.1 The Debugging Process 473 17.8.2 Psychological Considerations 474 17.8.3 Debugging Strategies 475 17.8.4 Correcting the Error 477 17.9 Summary 478 PROBLEMS AND POINTS TO PONDER 478 FURTHER READINGS AND INFORMATION SOURCES 479 CHAPTER 18 TESTING CONVENTIONAL APPLICATIONS 481 18.1 Software Testing Fundamentals 482 18.2 Internal and External Views of Testing 484 18.3 White-Box Testing 485 18.4 Basis Path Testing 485 18.4.1 Flow Graph Notation 485 18.4.2 Independent Program Paths 487 18.4.3 Deriving Test Cases 489 18.4.4 Graph Matrices 491 18.5 Control Structure Testing 492 18.5.1 Condition Testing 492 18.5.2 Data Flow Testing 493 18.5.3 Loop Testing 493 18.6 Black-Box Testing 495 18.6.1 Graph-Based Testing Methods 495 18.6.2 Equivalence Partitioning 497 18.6.3 Boundary Value Analysis 498 18.6.4 Orthogonal Array Testing 499 18.7 Model-Based Testing 502 18.8 Testing for Specialized Environments, Architectures, and Applications 503 18.8.1 Testing GUIs 503 18.8.2 Testing of Client-Server Architectures 503 18.8.3 Testing Documentation and Help Facilities 505 18.8.4 Testing for Real-Time Systems 506 18.9 Patterns for Software Testing 507 18.10 Summary 508 PROBLEMS AND POINTS TO PONDER 509 FURTHER READINGS AND INFORMATION SOURCES 510 CHAPTER 19 TESTING OBJECT-ORIENTED APPLICATIONS 511 19.1 Broadening the View of Testing 512 19.2 Testing OOA and OOD Models 513 pre75977_FM.qxd 11/27/08 6:38 PM Page xviii xviii TABLE OF CONTENTS 19.2.1 Correctness of OOA and OOD Models 513 19.2.2 Consistency of Object-Oriented Models 514 19.3 Object-Oriented Testing Strategies 516 19.3.1 Unit Testing in the OO Context 516 19.3.2 Integration Testing in the OO Context 516 19.3.3 Validation Testing in an OO Context 517 19.4 Object-Oriented Testing Methods 517 19.4.1 The Test-Case Design Implications of OO Concepts 518 19.4.2 Applicability of Conventional Test-Case Design Methods 518 19.4.3 Fault-Based Testing 519 19.4.4 Test Cases and the Class Hierarchy 519 19.4.5 Scenario-Based Test Design 520 19.4.6 Testing Surface Structure and Deep Structure 522 19.5 Testing Methods Applicable at the Class Level 522 19.5.1 Random Testing for OO Classes 522 19.5.2 Partition Testing at the Class Level 524 19.6 Interclass Test-Case Design 524 19.6.1 Multiple Class Testing 524 19.6.2 Tests Derived from Behavior Models 526 19.7 Summary 527 PROBLEMS AND POINTS TO PONDER 528 FURTHER READINGS AND INFORMATION SOURCES 528 CHAPTER 20 TESTING WEB APPLICATIONS 529 20.1 Testing Concepts for WebApps 530 20.1.1 Dimensions of Quality 530 20.1.2 Errors within a WebApp Environment 531 20.1.3 Testing Strategy 532 20.1.4 Test Planning 532 20.2 The Testing Process—An Overview 533 20.3 Content Testing 534 20.3.1 Content Testing Objectives 534 20.3.2 Database Testing 535 20.4 User Interface Testing 537 20.4.1 Interface Testing Strategy 537 20.4.2 Testing Interface Mechanisms 538 20.4.3 Testing Interface Semantics 540 20.4.4 Usability Tests 540 20.4.5 Compatibility Tests 542 20.5 Component-Level Testing 543 20.6 Navigation Testing 545 20.6.1 Testing Navigation Syntax 545 20.6.2 Testing Navigation Semantics 546 20.7 Configuration Testing 547 20.7.1 Server-Side Issues 547 20.7.2 Client-Side Issues 548 20.8 Security Testing 548 20.9 Performance Testing 550 20.9.1 Performance Testing Objectives 550 20.9.2 Load Testing 551 20.9.3 Stress Testing 552 pre75977_FM.qxd 11/27/08 6:38 PM Page xix TABLE OF CONTENTS xix 20.10 Summary 553 PROBLEMS AND POINTS TO PONDER 554 FURTHER READINGS AND INFORMATION SOURCES 555 CHAPTER 21 FORMAL MODELING AND VERIFICATION 557 21.1 The Cleanroom Strategy 558 21.2 Functional Specification 560 21.2.1 Black-Box Specification 561 21.2.2 State-Box Specification 562 21.2.3 Clear-Box Specification 562 21.3 Cleanroom Design 563 21.3.1 Design Refinement 563 21.3.2 Design Verification 564 21.4 Cleanroom Testing 566 21.4.1 Statistical Use Testing 566 21.4.2 Certification 567 21.5 Formal Methods Concepts 568 21.6 Applying Mathematical Notation for Formal Specification 571 21.7 Formal Specification Languages 573 21.7.1 Object Constraint Language (OCL) 574 21.7.2 The Z Specification Language 577 21.8 Summary 580 PROBLEMS AND POINTS TO PONDER 581 FURTHER READINGS AND INFORMATION SOURCES 582 CHAPTER 22 SOFTWARE CONFIGURATION MANAGEMENT 584 22.1 Software Configuration Management 585 22.1.1 An SCM Scenario 586 22.1.2 Elements of a Configuration Management System 587 22.1.3 Baselines 587 22.1.4 Software Configuration Items 589 22.2 The SCM Repository 590 22.2.1 The Role of the Repository 590 22.2.2 General Features and Content 591 22.2.3 SCM Features 592 22.3 The SCM Process 593 22.3.1 Identification of Objects in the Software Configuration 594 22.3.2 Version Control 595 22.3.3 Change Control 596 22.3.4 Configuration Audit 599 22.3.5 Status Reporting 600 22.4 Configuration Management for WebApps 601 22.4.1 Dominant Issues 601 22.4.2 WebApp Configuration Objects 603 22.4.3 Content Management 603 22.4.4 Change Management 606 22.4.5 Version Control 608 22.4.6 Auditing and Reporting 609 22.5 Summary 610 PROBLEMS AND POINTS TO PONDER 611 FURTHER READINGS AND INFORMATION SOURCES 612 pre75977_FM.qxd 11/27/08 6:38 PM Page xx xx TABLE OF CONTENTS CHAPTER 23 PRODUCT METRICS 613 23.1 A Framework for Product Metrics 614 23.1.1 Measures, Metrics, and Indicators 614 23.1.2 The Challenge of Product Metrics 615 23.1.3 Measurement Principles 616 23.1.4 Goal-Oriented Software Measurement 617 23.1.5 The Attributes of Effective Software Metrics 618 23.2 Metrics for the Requirements Model 619 23.2.1 Function-Based Metrics 620 23.2.2 Metrics for Specification Quality 623 23.3 Metrics for the Design Model 624 23.3.1 Architectural Design Metrics 624 23.3.2 Metrics for Object-Oriented Design 627 23.3.3 Class-Oriented Metrics—The CK Metrics Suite 628 23.3.4 Class-Oriented Metrics—The MOOD Metrics Suite 631 23.3.5 OO Metrics Proposed by Lorenz and Kidd 632 23.3.6 Component-Level Design Metrics 632 23.3.7 Operation-Oriented Metrics 634 23.3.8 User Interface Design Metrics 635 23.4 Design Metrics for WebApps 636 23.5 Metrics for Source Code 638 23.6 Metrics for Testing 639 23.6.1 Halstead Metrics Applied to Testing 639 23.6.2 Metrics for Object-Oriented Testing 640 23.7 Metrics for Maintenance 641 23.8 Summary 642 PROBLEMS AND POINTS TO PONDER 642 FURTHER READINGS AND INFORMATION SOURCES 643 PAR T FOUR MANAGING SOFTWARE PROJECTS 645 CHAPTER 24 PROJECT MANAGEMENT CONCEPTS 646 24.1 The Management Spectrum 647 24.1.1 The People 647 24.1.2 The Product 648 24.1.3 The Process 648 24.1.4 The Project 648 24.2 People 649 24.2.1 The Stakeholders 649 24.2.2 Team Leaders 650 24.2.3 The Software Team 651 24.2.4 Agile Teams 654 24.2.5 Coordination and Communication Issues 655 24.3 The Product 656 24.3.1 Software Scope 656 24.3.2 Problem Decomposition 656 24.4 The Process 657 24.4.1 Melding the Product and the Process 657 24.4.2 Process Decomposition 658 24.5 The Project 660 24.6 The W5HH Principle 661 pre75977_FM.qxd 11/27/08 6:38 PM Page xxi TABLE OF CONTENTS xxi 24.7 Critical Practices 662 24.8 Summary 663 PROBLEMS AND POINTS TO PONDER 663 FURTHER READINGS AND INFORMATION SOURCES 664 CHAPTER 25 PROCESS AND PROJECT METRICS 666 25.1 Metrics in the Process and Project Domains 667 25.1.1 Process Metrics and Software Process Improvement 667 25.1.2 Project Metrics 670 25.2 Software Measurement 671 25.2.1 Size-Oriented Metrics 672 25.2.2 Function-Oriented Metrics 673 25.2.3 Reconciling LOC and FP Metrics 673 25.2.4 Object-Oriented Metrics 675 25.2.5 Use-Case–Oriented Metrics 676 25.2.6 WebApp Project Metrics 677 25.3 Metrics for Software Quality 679 25.3.1 Measuring Quality 680 25.3.2 Defect Removal Efficiency 681 25.4 Integrating Metrics within the Software Process 682 25.4.1 Arguments for Software Metrics 683 25.4.2 Establishing a Baseline 683 25.4.3 Metrics Collection, Computation, and Evaluation 684 25.5 Metrics for Small Organizations 684 25.6 Establishing a Software Metrics Program 686 25.7 Summary 688 PROBLEMS AND POINTS TO PONDER 688 FURTHER READINGS AND INFORMATION SOURCES 689 CHAPTER 26 ESTIMATION FOR SOFTWARE PROJECTS 691 26.1 Observations on Estimation 692 26.2 The Project Planning Process 693 26.3 Software Scope and Feasibility 694 26.4 Resources 695 26.4.1 Human Resources 695 26.4.2 Reusable Software Resources 696 26.4.3 Environmental Resources 696 26.5 Software Project Estimation 697 26.6 Decomposition Techniques 698 26.6.1 Software Sizing 698 26.6.2 Problem-Based Estimation 699 26.6.3 An Example of LOC-Based Estimation 701 26.6.4 An Example of FP-Based Estimation 702 26.6.5 Process-Based Estimation 703 26.6.6 An Example of Process-Based Estimation 704 26.6.7 Estimation with Use Cases 705 26.6.8 An Example of Use-Case–Based Estimation 706 26.6.9 Reconciling Estimates 707 26.7 Empirical Estimation Models 708 26.7.1 The Structure of Estimation Models 709 26.7.2 The COCOMO II Model 709 26.7.3 The Software Equation 711 pre75977_FM.qxd 11/27/08 6:38 PM Page xxii xxii TABLE OF CONTENTS 26.8 Estimation for Object-Oriented Projects 712 26.9 Specialized Estimation Techniques 713 26.9.1 Estimation for Agile Development 713 26.9.2 Estimation for WebApp Projects 714 26.10 The Make/Buy Decision 715 26.10.1 Creating a Decision Tree 715 26.10.2 Outsourcing 717 26.11 Summary 718 PROBLEMS AND POINTS TO PONDER 719 FURTHER READINGS AND INFORMATION SOURCES 719 CHAPTER 27 PROJECT SCHEDULING 721 27.1 Basic Concepts 722 27.2 Project Scheduling 724 27.2.1 Basic Principles 725 27.2.2 The Relationship Between People and Effort 725 27.2.3 Effort Distribution 727 27.3 Defining a Task Set for the Software Project 728 27.3.1 A Task Set Example 729 27.3.2 Refinement of Software Engineering Actions 730 27.4 Defining a Task Network 731 27.5 Scheduling 732 27.5.1 Time-Line Charts 732 27.5.2 Tracking the Schedule 734 27.5.3 Tracking Progress for an OO Project 735 27.5.4 Scheduling for WebApp Projects 736 27.6 Earned Value Analysis 739 27.7 Summary 741 PROBLEMS AND POINTS TO PONDER 741 FURTHER READINGS AND INFORMATION SOURCES 743 CHAPTER 28 RISK MANAGEMENT 744 28.1 Reactive versus Proactive Risk Strategies 745 28.2 Software Risks 745 28.3 Risk Identification 747 28.3.1 Assessing Overall Project Risk 748 28.3.2 Risk Components and Drivers 749 28.4 Risk Projection 749 28.4.1 Developing a Risk Table 750 28.4.2 Assessing Risk Impact 752 28.5 Risk Refinement 754 28.6 Risk Mitigation, Monitoring, and Management 755 28.7 The RMMM Plan 757 28.8 Summary 759 PROBLEMS AND POINTS TO PONDER 759 FURTHER READINGS AND INFORMATION SOURCES 760 CHAPTER 29 MAINTENANCE AND REENGINEERING 761 29.1 Software Maintenance 762 29.2 Software Supportability 764 pre75977_FM.qxd 11/27/08 6:38 PM Page xxiii TABLE OF CONTENTS xxiii 29.3 Reengineering 764 29.4 Business Process Reengineering 765 29.4.1 Business Processes 765 29.4.2 A BPR Model 766 29.5 Software Reengineering 768 29.5.1 A Software Reengineering Process Model 768 29.5.2 Software Reengineering Activities 770 29.6 Reverse Engineering 772 29.6.1 Reverse Engineering to Understand Data 773 29.6.2 Reverse Engineering to Understand Processing 774 29.6.3 Reverse Engineering User Interfaces 775 29.7 Restructuring 776 29.7.1 Code Restructuring 776 29.7.2 Data Restructuring 777 29.8 Forward Engineering 778 29.8.1 Forward Engineering for Client-Server Architectures 779 29.8.2 Forward Engineering for Object-Oriented Architectures 780 29.9 The Economics of Reengineering 780 29.10 Summary 781 PROBLEMS AND POINTS TO PONDER 782 FURTHER READINGS AND INFORMATION SOURCES 783 PAR T FIVE ADVANCED TOPICS 785 CHAPTER 30 SOFTWARE PROCESS IMPROVEMENT 786 30.1 What Is SPI? 787 30.1.1 Approaches to SPI 787 30.1.2 Maturity Models 789 30.1.3 Is SPI for Everyone? 790 30.2 The SPI Process 791 30.2.1 Assessment and Gap Analysis 791 30.2.2 Education and Training 793 30.2.3 Selection and Justification 793 30.2.4 Installation/Migration 794 30.2.5 Evaluation 795 30.2.6 Risk Management for SPI 795 30.2.7 Critical Success Factors 796 30.3 The CMMI 797 30.4 The People CMM 801 30.5 Other SPI Frameworks 802 30.6 SPI Return on Investment 804 30.7 SPI Trends 805 30.8 Summary 806 PROBLEMS AND POINTS TO PONDER 806 FURTHER READINGS AND INFORMATION SOURCES 807 CHAPTER 31 EMERGING TRENDS IN SOFTWARE ENGINEERING 808 31.1 Technology Evolution 809 31.2 Observing Software Engineering Trends 811 pre75977_FM.qxd 12/3/08 1:55 PM Page xxiv xxiv TABLE OF CONTENTS 31.3 Identifying “Soft Trends” 812 31.3.1 Managing Complexity 814 31.3.2 Open-World Software 815 31.3.3 Emergent Requirements 816 31.3.4 The Talent Mix 816 31.3.5 Software Building Blocks 817 31.3.6 Changing Perceptions of “Value” 818 31.3.7 Open Source 818 31.4 Technology Directions 819 31.4.1 Process Trends 819 31.4.2 The Grand Challenge 821 31.4.3 Collaborative Development 822 31.4.4 Requirements Engineering 824 31.4.5 Model-Driven Software Development 825 31.4.6 Postmodern Design 825 31.4.7 Test-Driven Development 826 31.5 Tools-Related Trends 827 31.5.1 Tools That Respond to Soft Trends 828 31.5.2 Tools That Address Technology Trends 830 31.6 Summary 830 PROBLEMS AND POINTS TO PONDER 831 FURTHER READINGS AND INFORMATION SOURCES 831 CHAPTER 32 CONCLUDING COMMENTS 833 32.1 The Importance of Software—Revisited 834 32.2 People and the Way They Build Systems 834 32.3 New Modes for Representing Information 835 32.4 The Long View 837 32.5 The Software Engineer’s Responsibility 838 32.6 A Final Comment 839 APPENDIX 1 AN INTRODUCTION TO UML 841 APPENDIX 2 OBJECT-ORIENTED CONCEPTS 863 REFERENCES 871 INDEX 889 pre75977_FM.qxd 11/27/08 6:38 PM Page xxv P REFACE W hen computer software succeeds—when it meets the needs of the people who use it, when it performs flawlessly over a long period of time, when it is easy to modify and even easier to use—it can and does change things for the better. But when software fails—when its users are dissatisfied, when it is error prone, when it is difficult to change and even harder to use—bad things can and do happen. We all want to build software that makes things better, avoiding the bad things that lurk in the shadow of failed efforts. To succeed, we need discipline when software is designed and built. We need an engineer- ing approach. It has been almost three decades since the first edition of this book was written. During that time, software engineering has evolved from an obscure idea practiced by a relatively small number of zealots to a legitimate engineering discipline. Today, it is recognized as a subject worthy of serious research, conscientious study, and tumultuous debate. Through- out the industry, software engineer has replaced programmer as the job title of preference. Software process models, software engineering methods, and software tools have been adopted successfully across a broad spectrum of industry segments. Although managers and practitioners alike recognize the need for a more disciplined approach to software, they continue to debate the manner in which discipline is to be applied. Many individuals and companies still develop software haphazardly, even as they build systems to service today’s most advanced technologies. Many professionals and students are unaware of modern methods. And as a result, the quality of the software that we produce suffers, and bad things happen. In addition, debate and controversy about the true nature of the software engineering approach continue. The status of software engi- neering is a study in contrasts. Attitudes have changed, progress has been made, but much remains to be done before the discipline reaches full maturity. The seventh edition of Software Engineering: A Practitioner’s Approach is intended to serve as a guide to a maturing engineering discipline. Like the six editions that preceded it, the seventh edition is intended for both students and practitioners, retaining its appeal as a guide to the industry professional and a comprehensive introduction to the student at the upper-level undergraduate or first-year graduate level. The seventh edition is considerably more than a simple update. The book has been revised and restructured to improve pedagogical flow and emphasize new and important software engineering processes and practices. In addition, a revised and updated “support system,” illustrated in the figure, provides a comprehensive set of student, instructor, and professional resources to complement the content of the book. These resources are pre- sented as part of a website (www.mhhe.com/ pressman) specifically designed for Software Engineering: A Practitioner’s Approach. The Seventh Edition. The 32 chapters of the seventh edition have been reorganized into five parts. This organization, which differs considerably from the sixth edition, has been done to better compartmentalize topics and assist instructors who may not have the time to complete the entire book in one term. xxv pre75977_FM.qxd 11/27/08 6:39 PM Page xxvi xxvi PREFACE Support Practice System for Chapter quizzes SEPA, 7/e study guides Solved problems Other Student SE resources topics Web resources Instructor (1,000+ links) manual Power- point Reference library slides (500+ links) Checklists Instructor Work product templates SEPA resources Tiny tools 7/e Adaptable process model Test Umbrella activities task set bank Comprehensive case study Professional resources Industry comment Distance learning Part 1, The Process, presents a variety of different views of software process, consider- ing all important process models and addressing the debate between prescriptive and agile process philosophies. Part 2, Modeling, presents analysis and design methods with an emphasis on object-oriented techniques and UML modeling. Pattern-based design and design for Web applications are also considered. Part 3, Quality Management, presents the concepts, procedures, techniques, and methods that enable a software team to assess software quality, review software engineering work products, conduct SQA procedures, and apply an effective testing strategy and tactics. In addition, formal modeling and veri- fication methods are also considered. Part 4, Managing Software Projects, presents topics that are relevant to those who plan, manage, and control a software development project. Part 5, Advanced Topics, considers software process improvement and software engineer- ing trends. Continuing in the tradition of past editions, a series of sidebars is used through- out the book to present the trials and tribulations of a (fictional) software team and to provide supplementary materials about methods and tools that are relevant to chapter topics. Two new appendices provide brief tutorials on UML and object-oriented thinking for those who may be unfamiliar with these important topics. pre75977_FM.qxd 11/27/08 6:39 PM Page xxvii PREFACE xxvii The five-part organization of the seventh edition enables an instructor to “cluster” topics based on available time and student need. An entire one-term course can be built around one or more of the five parts. A software engineering survey course would select chapters from all five parts. A software engineering course that emphasizes analysis and design would select topics from Parts 1 and 2. A testing-oriented software engineering course would select topics from Parts 1 and 3, with a brief foray into Part 2. A “manage- ment course” would stress Parts 1 and 4. By organizing the seventh edition in this way, I have attempted to provide an instructor with a number of teaching options. In every case, the content of the seventh edition is complemented by the following elements of the SEPA, 7/e Support System. Student Resources. A wide variety of student resources includes an extensive online learning center encompassing chapter-by-chapter study guides, practice quizzes, prob- lem solutions, and a variety of Web-based resources including software engineering checklists, an evolving collection of “tiny tools,” a comprehensive case study, work prod- uct templates, and many other resources. In addition, over 1000 categorized Web Refer- ences allow a student to explore software engineering in greater detail and a Reference Library with links to over 500 downloadable papers provides an in-depth source of advanced software engineering information. Instructor Resources. A broad array of instructor resources has been developed to supplement the seventh edition. These include a complete online Instructor’s Guide (also downloadable) and supplementary teaching materials including a complete set of over 700 PowerPoint Slides that may be used for lectures, and a test bank. Of course, all resources available for students (e.g., tiny tools, the Web References, the downloadable Reference Library) and professionals are also available. The Instructor’s Guide for Software Engineering: A Practitioner’s Approach presents sug- gestions for conducting various types of software engineering courses, recommendations for a variety of software projects to be conducted in conjunction with a course, solutions to selected problems, and a number of useful teaching aids. Professional Resources. A collection of resources available to industry practitioners (as well as students and faculty) includes outlines and samples of software engineering documents and other work products, a useful set of software engineering checklists, a catalog of software engineering (CASE) tools, a comprehensive collection of Web-based resources, and an “adaptable process model” that provides a detailed task breakdown of the software engineering process. When coupled with its online support system, the seventh edition of Software Engi- neering: A Practitioner’s Approach, provides flexibility and depth of content that cannot be achieved by a textbook alone. Acknowledgments. My work on the seven editions of Software Engineering: A Practi- tioner’s Approach has been the longest continuing technical project of my life. Even when the writing stops, information extracted from the technical literature continues to be assimilated and organized, and criticism and suggestions from readers worldwide is eval- uated and cataloged. For this reason, my thanks to the many authors of books, papers, and articles (in both hardcopy and electronic media) who have provided me with addi- tional insight, ideas, and commentary over nearly 30 years. Special thanks go to Tim Lethbridge of the University of Ottawa, who assisted me in the development of UML and OCL examples and developed the case study that accompa- nies this book, and Dale Skrien of Colby College, who developed the UML tutorial in pre75977_FM.qxd 11/27/08 6:39 PM Page xxviii xxviii PREFACE Appendix 1. Their assistance and comments were invaluable. Special thanks also go to Bruce Maxim of the University of Michigan–Dearborn, who assisted me in developing much of the pedagogical website content that accompanies this book. Finally, I wish to thank the reviewers of the seventh edition: Their in-depth comments and thoughtful criticism have been invaluable. Osman Balci, SK Jain, Virginia Tech University National Institute of Technology Hamirpur Max Fomitchev, Saeed Monemi, Penn State University Cal Poly Pomona Jerry (Zeyu) Gao, Ahmed Salem, San Jose State University California State University Guillermo Garcia, Vasudeva Varma, Universidad Alfonso X Madrid IIIT Hyderabad Pablo Gervas, Universidad Complutense de Madrid The content of the seventh edition of Software Engineering: A Practitioner’s Approach has been shaped by industry professionals, university professors, and students who have used earlier editions of the book and have taken the time to communicate their sugges- tions, criticisms, and ideas. My thanks to each of you. In addition, my personal thanks go to our many industry clients worldwide, who certainly have taught me as much or more than I could ever teach them. As the editions of this book have evolved, my sons, Mathew and Michael, have grown from boys to men. Their maturity, character, and success in the real world have been an inspiration to me. Nothing has filled me with more pride. And finally, to Barbara, my love and thanks for tolerating the many, many hours in the office and encouraging still another edition of “the book.” Roger S. Pressman pre75977_ch01.qxd 11/27/08 3:11 PM Page 1 CHAPTER SOFTWARE AND SOFTWARE ENGINEERING 1 KEY e had the classic look of a senior executive for a major software CONCEPTS application domains........7 H company—mid-40s, slightly graying at the temples, trim and athletic, with eyes that penetrated the listener as he spoke. But what he said shocked me. “Software is dead.” characteristics of I blinked with surprise and then smiled. “You’re joking, right? The world is software.......4 driven by software and your company has profited handsomely because of it. It framework isn’t dead! It’s alive and growing.” activities......15 He shook his head emphatically. “No, it’s dead... at least as we once knew it.” legacy software..9 I leaned forward. “Go on.” practice.......17 principles......19 He spoke while tapping the table for emphasis. “The old-school view of software software—you buy it, you own it, and it’s your job to manage it—that’s coming to engineering....12 an end. Today, with Web 2.0 and pervasive computing coming on strong, we’re software myths..21 going to be seeing a completely different generation of software. It’ll be delivered software process..14 via the Internet and will look exactly like it’s residing on each user’s computing umbrella device... but it’ll reside on a far-away server.” activities......16 WebApps......10 QUICK What is it? Computer software is Software engineering is important because it LOOK the product that software profession- enables us to build complex systems in a timely als build and then support over the manner and with high quality. long term. It encompasses programs What are the steps? You build computer soft- that execute within a computer of any size and ware like you build any successful product, by architecture, content that is presented as the applying an agile, adaptable process that leads computer programs execute, and descriptive to a high-quality result that meets the needs of information in both hard copy and virtual forms the people who will use the product. You apply that encompass virtually any electronic media. a software engineering approach. Software engineering encompasses a process, a What is the work product? From the point of collection of methods (practice) and an array view of a software engineer, the work product is of tools that allow professionals to build high- the set of programs, content (data), and other quality computer software. work products that are computer software. But Who does it? Software engineers build and sup- from the user’s viewpoint, the work product is port software, and virtually everyone in the indus- the resultant information that somehow makes trialized world uses it either directly or indirectly. the user’s world better. Why is it important? Software is important How do I ensure that I’ve done it right? because it affects nearly every aspect of our Read the remainder of this book, select those lives and has become pervasive in our com- ideas that are applicable to the software that merce, our culture, and our everyday activities. you build, and apply them to your work. 1 pre75977_ch01.qxd 11/27/08 3:11 PM Page 2 2 CHAPTER 1 SOFTWARE AND SOFTWARE ENGINEERING I had to agree. “So, your life will be much simpler. You guys won’t have to worry about five different versions of the same App in use across tens of thousands of users.” He smiled. “Absolutely. Only the most current version residing on our servers. When we make a change or a correction, we supply updated functionality and content to every user. Everyone has it instantly!” I grimaced. “But if you make a mistake, everyone has that instantly as well.” He chuckled. “True, that’s why we’re redoubling our efforts to do even better software engineering. Problem is, we have to do it ‘fast’ because the market has accelerated in every application area.” I leaned back and put my hands behind my head. “You know what they say,... you can have it fast, you can have it right, or you can have it cheap. Pick two!” “I’ll take it fast and right,” he said as he began to get up. I stood as well. “Then you really do need software engineering.” “I know that,” he said as he began to move away. “The problem is, we’ve got to convince still another generation of techies that it’s true!” Is software really dead? If it was, you wouldn’t be reading this book! Computer software continues to be the single most important technology on the world stage. And it’s also a prime example of the law of unintended consequences. Fifty years ago no one could have predicted that software would become an indis- uote: pensable technology for business, science, and engineering; that software would “Ideas and enable the creation of new technologies (e.g., genetic engineering and nanotech- technological nology), the extension of existing technologies (e.g., telecommunications), and the discoveries are the radical change in older technologies (e.g., the printing industry); that software would driving engines of be the driving force behind the personal computer revolution; that shrink-wrapped economic growth.” software products would be purchased by consumers in neighborhood malls; that Wall Street software would slowly evolve from a product to a service as “on-demand” soft