Requirements Engineering for Software and Systems. Phillip A. Laplante. CRC Press. Taylor S* Francis Group Boca Raton London New York

Size: px

Start display at page:

Download "Requirements Engineering for Software and Systems. Phillip A. Laplante. CRC Press. Taylor S* Francis Group Boca Raton London New York"

Natalie Ford
6 years ago
Views:

1 Requirements Engineering for Software and Systems Phillip A. Laplante (g) CRC Press Taylor S* Francis Group Boca Raton London New York CRC Press is an imprint of the Taylor & Francis Group, an informa business AN AUERBACH BOOK

Contents Acknowledgments Introduction About the Author xv xvii xxi 1 Introduction to Requirements Engineering 1 Motivation 1 What Is Requirements Engineering?

2 Contents Acknowledgments Introduction About the Author xv xvii xxi 1 Introduction to Requirements Engineering 1 Motivation 1 What Is Requirements Engineering? 2 You Probably Don't Do Enough Requirements Engineering 3 What Are Requirements? 4 Requirements Versus Goals 4 Requirements Level Classification 4 Requirements Specifications Types 6 Functional Requirements 6 Nonfunctional Requirements 7 Domain Requirements 10 Domain Vocabulary Understanding 11 Requirements Engineering Activities 11 Requirements Elicitation/Discovery 11 Requirements Analysis and Reconciliation 12 Requirements Representation and Modeling 12 Requirements Validation 12 Requirements Management 13 The Requirements Engineer 13 Requirements Engineering Paradigms 13 Requirements Engineer as Software Systems Engineer 14 Requirements Engineer as Subject Matter Expert 14 Requirements Engineer as Architect 14 Requirements Engineer as Business Process Expert 14 Ignorance as Virtue 15 Role of the Customer? 15 vii

viii Contents Problems with Traditional Requirements Engineering 16 Complexity 17 Four Dark Corners (Zave and Jackson) 18 Difficulties in Enveloping System Behavior 19 The Danger of "All" in

3 viii Contents Problems with Traditional Requirements Engineering 16 Complexity 17 Four Dark Corners (Zave and Jackson) 18 Difficulties in Enveloping System Behavior 19 The Danger of "All" in Specifications 21 References 22 2 Mission Statement, Customers, and Stakeholders 23 Mission Statements 23 Encounter with a Customer? 24 Stakeholders 26 Negative Stakeholders 27 Stakeholder Identification 27 Stakeholder Questions 27 Stakeholder/Customer Classes 29 Customer Wants and Needs 30 What Do Customers Want? 30 What Don't Customers Want? 33 Why Do Customers Change Their Minds? 34 Stakeholder Prioritization 35 Communicating with Customers and Other Stakeholders 36 Managing Expectations 37 Stakeholder Negotiations 38 References 40 3 Requirements Elicitation 41 Introduction 41 Elicitation Techniques Survey 42 Brainstorming 42 Card Sorting 42 Designer as Apprentice 44 Domain Analysis 45 Ethnographic Observation 45 Goal-Based Approaches 46 Group Work 48 Interviews 48 Introspection 50 Joint Application Design (JAD) 50 Laddering 51 Protocol Analysis 52 Prototyping 53 Quality Function Deployment 54 Questionnaires 55

Contents ix Repertory Grids 56 Scenarios 57 Task Analysis 57 User Stories 58 Viewpoints 59 Workshops 60 Ehcitation Summary 60 Which Combination of Requirements Ehcitation Techniques Should Be Used?

4 Contents ix Repertory Grids 56 Scenarios 57 Task Analysis 57 User Stories 58 Viewpoints 59 Workshops 60 Ehcitation Summary 60 Which Combination of Requirements Ehcitation Techniques Should Be Used? 60 Prevalence of Requirements Ehcitation Techniques 63 Ehcitation Support Technologies 63 Using Wikis for Requirements Ehcitation 63 Mobile Technologies 65 Content Analysis 65 References 66 4 Writing the Requirements Document 69 Requirements Representation Approaches 69 IEEE Standard IEEE Standard 830 Recommendations on Representing Non-Functional Requirements 72 IEEE Standard 830 Recommendations on Representing Functional Requirements 73 Operating System 74 Command Validation 75 ISO/IEC Standard Use Cases 78 Behavioral Specifications 79 The Requirements Document 81 Users of a Requirements Document 82 Requirements Document Requirements 82 Preferred Writing Style 83 Text Structure 83 Best Practices and Recommendations 84 References 86 5 Requirements Risk Management 87 What Is Requirements Risk Management? 87 Requirements Validation and Verification 89 Techniques for Requirements V&V 90 Goal-Based Requirements Analysis 90 Requirements Understanding 91

x Contents Validating Requirements Use Cases 92 Prototyping 92 The Requirements Validation Matrix 92 The Importance of Measurement in Requirements Verification and Validation 93 Goal/Question/Metric

5 x Contents Validating Requirements Use Cases 92 Prototyping 92 The Requirements Validation Matrix 92 The Importance of Measurement in Requirements Verification and Validation 93 Goal/Question/Metric Analysis 94 Standards for Verification and Validation 95 IEEE Standard Correctness 97 Ambiguity 97 Completeness 98 Consistency 99 Ranking 99 Verifiability 100 Modifiability 100 Traceability 100 NASA Requirements Testing 101 NASA ARM Tool 101 Imperatives 103 Continuances 103 Directives 105 Options 105 Weak Phrases 105 Incomplete 106 Subjects 107 Specification Depth 107 Readability Statistics 108 Summary of NASA Metrics 108 References Ill 6 Formal Methods 113 Motivation 113 What Are Formal Methods? 114 A Little History 115 Using Formal Methods 116 Formal Methods Types 116 Examples 117 Formalization of Train Station in В 117 Formalization of Space Shuttle Flight Software Using МигФ 121 Formalization of an Energy Management System Using Category Theory 122 Example: An Energy Management System 124 Requirements Validation 126

Contents xi Theorem Proving 128 Program Correctness 128 Hoare Logic 129 Model Checking 133 Objections, Myths, and Limitations 134 Objections and Myths 134 Limitations of Formal Methods 135 Final

6 Contents xi Theorem Proving 128 Program Correctness 128 Hoare Logic 129 Model Checking 133 Objections, Myths, and Limitations 134 Objections and Myths 134 Limitations of Formal Methods 135 Final Advice 136 References Requirements Specification and Agile Methodologies 139 Introduction to Agile Methodologies 139 Principles Behind the Agile Manifesto 140 Extreme Programming (XP) 142 Scrum 143 Requirements Engineering for Agile Methodologies 144 General Practices in Agile Methodologies 145 Agile Requirements Best Practices 145 Requirements Engineering in XP 147 Requirements Engineering in Scrum 147 Writing User Stories 148 Agile Requirements Engineering 150 Challenges for Requirements Engineering in Agile Methodologies 152 Bibliography Tool Support for Requirements Engineering 155 Introduction 155 Traceability Support 156 Commercial Requirements Engineering Tools 159 DOORS 160 Rational RequisitePro 160 Requirements and Traceability Management 160 CaliberRM 160 QFD/Capture 161 Open Source Requirements Engineering Tools 161 FreeMind 161 Open Source Requirements Management Tool (OSRMT) 163 FitNesse 166 Requirements Engineering Tool Best Practices 167 References Requirements Management 171 Introduction 171 Managing Divergent Agendas 171

xii Contents Expectation Revisited: Pascal's Wager 173 Global Requirements Management 174 Antipatterns in Requirements Management 176 Environmental Antipatterns 177 Divergent Goals 177 Process Clash

7 xii Contents Expectation Revisited: Pascal's Wager 173 Global Requirements Management 174 Antipatterns in Requirements Management 176 Environmental Antipatterns 177 Divergent Goals 177 Process Clash 178 Management Antipatterns 178 Metric Abuse 178 Mushroom Management 179 Other Paradigms for Requirements Management 180 Requirements Management and Improvisational Comedy 180 Requirements Management as Script-writing 181 Reference Models for Requirements Management 182 ISO (1997) 183 Six Sigma 183 Capability Maturity Model (CMMI) 184 IEEE IEEE (2002) 185 ISO/IEC A Case Study: FBI Virtual Case File 186 References Value Engineering of Requirements 189 What, Why, When, and How of Value Engineering? 189 What Is Value Engineering? 189 When Does Value Engineering Occur? 190 Estimating Using COCOMO and Its Derivatives 190 COCOMO 191 WEBMO 192 COSYSMO 193 Estimating Using Function Points 194 Function Point Cost Drivers 194 Feature Points 196 Use Case Points 196 Requirements Feature Cost Justification 197 Return on Investment 197 Net Present Value 198 Internal Rate of Return 199 Profitability Index 200 Payback Period 201 Discounted Payback Period 201 References 202

8 Contents xiii Appendix Software Requirements Specification for a Smart Home, Version 2.0, September 20, Glossary 229 Index 233

The Art of Agile Practice

The Art of Agile Practice A Composite Approach for Projects and Organizations Bhuvan Unhelkar Lap) CRC Press VV^ ^^-""^ J Taylor & Francis Group Boca Raton London New York CRC Press is an imprint of the