Requirements Engineering for Software and Systems

266 Pages·2009·1.951 MB·English

by  Phillip A. Laplante

Titles in the
Auerbach Series on Applied Software Engineering
Phillip A. Laplante, Pennsylvania State University, Series Editor
Requirements Engineering for Software and Systems
Phillip A. Laplante
1-4200-6467-3
Building Software: A Practioner’s Guide
Nikhilesh Krishnamurthy and Amitabh Saran
0-8493-7303-4
Global Software Development Handbook
Raghvinder Sangwan, Matthew Bass, Neel Mullick, Daniel J. Paulish,
and Juergen Kazmeier
0-8493-9384-1
Antipatterns: Identification, Refactoring, and Management
Phillip A. Laplante and Colin J. Neill
0-8493-2994-9
Software Engineering Quality Practices
Ronald Kirk Kandt
0-8493-4633-9
Boca Raton London New York
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For my mother

Contents
Acknowledgments .........................................................................................xv
Introduction ................................................................................................xvii
About the Author .........................................................................................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 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
Elicitation Summary ..................................................................................60
Which Combination of Requirements Elicitation Techniques
Should Be Used? ...............................................................................60
Prevalence of Requirements Elicitation Techniques ..........................63
Elicitation Support Technologies ...............................................................63
Using Wikis for Requirements Elicitation.........................................63
Mobile Technologies .........................................................................65
Content Analysis ..............................................................................65
References .................................................................................................66
4 Writing the Requirements Document ..................................................69
Requirements Representation Approaches .................................................69
IEEE Standard 830-1998 ...........................................................................71
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 25030 .................................................................76
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