Agile software engineering

312 Pages·2008·2.915 MB·English

by  Orit Hazzan, Yael Dubinsky

Orit Hazzan and Yael Dubinsky
Agile Software
Engineering
1 3
OritHazzan,BSc,MSc,PhD,MBA YaelDubinsky,BSc,MSc,PhD
DepartmentofEducationinTechnology DepartmentofComputerScience
andScience Technion–IsraelInstitute
Technion–IsraelInstituteofTechnology ofTechnology
Haifa,Israel Haifa,Israel
Serieseditor
IanMackie,E(cid:2)colePolytechnique,FranceandUniversityofSussex,UK
Advisoryboard
SamsonAbramsky,UniversityofOxford,UK
ChrisHankin,ImperialCollegeLondon,UK
DexterKozen,CornellUniversity,USA
AndrewPitts,UniversityofCambridge,UK
HanneRiisNielson,TechnicalUniversityofDenmark,Denmark
StevenSkiena,StonyBrookUniversity,USA
IainStewart,UniversityofDurham,UK
DavidZhang,TheHongKongPolytechnicUniversity,HongKong
UndergraduateTopicsinComputerScienceISSN1863-7310
ISBN:978-1-84800-198-5 e-ISBN:978-1-84800-199-2
DOI:10.1007/978-1-84800-199-2
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Preface
Overview and Goals
The agile approach for software development has been applied more and more
extensivelysincethemidninetiesofthe20thcentury.Thoughthereareonlyabout
ten years of accumulated experience using the agile approach, it is currently
conceivedasoneofthemainstreamapproachesforsoftwaredevelopment.
This book presents a complete software engineering course from the agile
angle.Ourintentionistopresenttheagileapproachinaholisticandcomprehen-
sivelearningenvironmentthatfitsbothindustryandacademiaandinspiresthe
spiritofagilesoftwaredevelopment.
Agilesoftwareengineeringisreviewedinthisbookthroughthefollowingthree
perspectives:
l The Human perspective, which includes cognitive and social aspects, and
referstolearningandinterpersonalprocessesbetweenteammates,customers,
andmanagement.
l The Organizational perspective, which includes managerial and cultural
aspects,andreferstosoftwareprojectmanagementandcontrol.
l TheTechnologicalperspective,whichincludespracticalandtechnicalaspects,
andreferstodesign,testing,andcoding,aswellastointegration,delivery,and
maintenanceofsoftwareproducts.
Specifically, we explain and analyze how the explicit attention that agile
software developmentgives these perspectives and their interconnections,helps
viii Preface
itcopewiththechallengesofsoftwareprojects.Thismultifacetedperspectiveon
software development processes is reflected in this book, among other ways, by
the chapter titles, which specify dimensions of software development projects
suchasquality,time,abstraction,andmanagement,ratherthanspecificproject
stages,phases,orpractices.
Toshare withthereaders thismultifacetedperspective,we usetheHuman,
Organizational,andTechnical(HOT)scalefor softwaredevelopmentapproaches.
HOT
Forexample,whenwerefertoteamworkorabstractionlevels,weemphasizethe
Human perspective; when software management issues are addressed, the
Organizational perspective is emphasized; similarly, when the actual perfor-
HOT
mance of test-driven development is described, the Technological aspect is
highlighted. When the HOT? sign appears, the readers are invited to suggest
their own HOT perspective.
Agile software development values these three perspectives. Therefore, in
HOT
manycases,morethanoneperspectiveisilluminatedbytheagileapproachwith
respecttoaspecifictopic.Yetevenwhenmorethanoneperspectiveissignificant
withrespecttoaspecifictopic,wediscussfromtimetotimeonlyoneortwomain
perspective(s),andthereadersareinvitedtocompletethepicture.
Thebookisbasedontheauthors’comprehensiveexperienceofteachingand
implementing agile software development over the past six years. A course on
agile software engineering has been shaped during these years, in an iterative
process that was accompanied by an ongoing research project. This course is
presentedinthisbook.Inparalleltothecoursecreationandshapingprocess,the
agile approach has emerged and spread, becoming one of the worldwide main-
streamapproachesforsoftwareprojectmanagement.
Organization and Features
This textbook guides a fourteen-week/session course on software engineering
from the agile perspective and can be used on a weekly basis. It is intended for
all who practice, research, teach, and learn software development both in
academiaandindustry.Itdiscusseshowagileteamsliveandfunctioninsoftware
development environments, how they achieve their goals, and how they act
professionally in their environments. Specifically, the themes presented in the
book,suchasteamwork,time,quality,learning,trust,andculture,arereviewed
from human, organizational, and technological perspectives, at the individual,
team,andorganizationallevels,andareillustratedwithcasestudiestakenfrom
industryandacademia.
The fourteen chapters of the book are organized in three iterations. This
structureenablesustorevisitthevarioussubjectsseveraltimesduringthecourse,
Preface ix
Table1. Bookstructure
Iteration Chapter# Topic
I 1 IntroductiontoAgileSoftwareDevelopment
2 Teamwork
3 CustomersandUsers
4 Time
5 Measures
6 Quality
7 Learning
II 8 Abstraction
9 Trust
10 Globalization
11 Reflection
III 12 Change
13 Leadership
14 DeliveryandCyclicality
as well as to guide the development of a one-release software product. Table 1
presentsthebook’sstructurebookandthetopicofeachchapter.
Eachchapterincludesatheoreticalapproachtoaspecifictopic,asectionthat
referstothegiventopicinlearningenvironments,andavarietyofquestionsand
tasksforfurtherelaboration.
The Academic Community
This book on agile software engineering can be used by instructors, academic
coaches, and students as atextbookduring afourteen-weeksemester, either for
thecommonlytitled‘‘IntroductiontoSoftwareEngineering’’courseorthe‘‘Soft-
wareEngineeringMethods’’course.
Thecourseisbasedontwomaincomponentsthatprogressinparallelandare
closelycorrelatedwitheachother.Thefirstcomponentistheoreticalandcanbe
used in the lecture hall or the class; the second is software project development
guidedbytheagileapproachthattakesplaceinaphysicallearningenvironment
thatwecallastudioorlab.
This book is written for the entire course community---students, instructors,
and academic coaches. Students are the learners who become familiar with the
agile approach both from a theoretical perspective (in the lectures) and from a
practicalperspective(inthestudio).Instructorsaretheteachersof thecourse’s
theoreticalideas,whousuallyteachinaclassorinalecturehall;yet,interactive
teaching and active learning can be facilitated in this setting as well. The aca-
demiccoachesarethepractitionerswhoguidethesoftwareprojectdevelopment
x Preface
in the studio (we elaborate on this role in Chapter 1, Introduction to Agile
SoftwareEngineering).
The positive results of agile software projects, as elaborated throughout the
various chapters of the book, are not the only motive for this course, which
presents the field of software engineering from the agile perspective. There are
threeadditionalcharacteristicsofthecourse,whichareespeciallyrelevantwhen
itistaughtinacademia.
First,theagileapproachwasdevelopedbypractitionersworkinginthesoft-
wareindustry,andhasbecomemainstreaminthatindustry.Therefore,itmakes
sensetoarticulateitsnatureandmainconceptstoprospectivesoftwareengineers
intheframeworkofacoursethatdealswithsoftwareengineering.
Second,teachingasoftwareengineeringcoursewithintheframeworkofagile
software development emphasizes a comprehensive image of the field. This is
because agile software development explicitly addresses human, organizational,
andtechnologicalaspectsofthesoftwaredevelopmentprocesswithrespecttoall
players participating in that process. Thus, the agile approach serves as an
opportunitytodrawthiscomprehensiveandcomplexpictureofthefield.
Third,accordingtotheSoftwareEngineering2004Curriculum,developedby
theIEEEComputerSocietyandtheAssociationforComputingMachineryJoint
Task Force (see http://sites.computer.org/ccse/SE2004Volume.pdf), software
engineering students should acquire additional skills beyond the technical
and scientific ones. One illustrative example is teamwork-related skills. Since
teamworkisoneofthebasicideasofagilesoftwaredevelopment,itisonlynatural
to integrate teamwork-oriented skills in the teaching and learning process of
softwareengineeringfromtheagileperspective.Furthermore,sinceitisnatural
toteachagilesoftwaredevelopmentinateamwork-orientedenvironment,thereis
noneedtointroducethetopicofteamworkartificially;rather,ateamwork-based
learningenvironmentcanbeusedtoteachthistopic.Thiselementisemphasized
mainly,butnotonly,inthestudioelementofthecourse.
SuggestedUses in an Academic Environment
Each chapter presentsafull week ofthecourse: twoweeklylecturehoursanda
four-hourweeklystudiomeeting.Thefirstpartofeachchapterincludescontents
suitabletobepresentedinthelecture.Thispartusuallypresentsmaterialbeyond
whatitispossibletoteachinatwo-hourlecture.Therefore,itisadvisablenotto
trytodeliverallthecontentintwohours;rather,wesuggestselectingfromeach
chapter the most relevant topics to be discussed with each particular class of
students. It is also advisable to encourage in the lectures some active learning
elements,asissuggestedinthevariouschapters.Thesecondpartofeachchapter
Preface xi
addressestheteachingandlearningofthechaptertopic.Itpresentsteachingand
learningprinciplesandtheactivitiesconductedinthestudioeachweek.
As preparation for the next week’s lectures and studio meeting, instructors
and academic coaches can ask the students to read the relevant chapter and to
workon selected activities presented throughout the bodyofeach chapter. The
students’preparationforthelecturewill alsopartially solvethetime limitation
problemofaddressingalltheideaspresented.
Finally,thoughthebookpresentsafullfourteen-weeksemestercourse,which
consists of two weekly lecture hours and four-hour weekly studio meetings, it is
possibletoteachonlyonecomponentofthecourse.Thematerialprovidedinthis
bookenableseachinstructor/academiccoachtomaketheneededadjustments.
The Industrial Community
Sinceagiledevelopmenthasbecomeoneofthemainstreamapproachesformana-
gingsoftwareprojects,moreandmoresoftwareorganizationsofdifferentsizesand
typesaskthemselveswhethertheagileapproachfitsthem.Evenwhenitisfound
thatagilesoftwaredevelopmentisrelevantforagivenorganization,questionssuch
as the following are usually asked: How can we manage a transition to the agile
software development process? How can our organization cope with the changes
requiredforsuchatransition?Howcanweteachagilesoftwaredevelopmenttoall
thesoftwarepractitionersandalltheothersoftwareproject’sstakeholders?
Thisbook,whenusedinanindustrialsetting,aimstoanswertheseandother
relevant questions which software organizations face when dealing with the
transition to agile software development. For example, in Chapter 12, Change,
wediscusshowtoinitiateatransitionprocesstoagilesoftwaredevelopmentinan
organization. When the organization has already transitioned to agile software
development, the book can also be used for answering questions related to the
actual implementation of agile software development in the organization. For
example,inChapter2,Teamwork,wediscusshowteamscanbeformedtoexploit
theirpotential,toavoidconflicts,andtosolvedilemmas.
SuggestedUses in an IndustrialEnvironment
This book can be used in industrial settings by coaches of software teams, soft-
wareteamleaders,andfacilitatorsofagilesoftwaredevelopmentworkshops,both
for the teaching and learning of agile software development, as well as for its
implementation.Thebookcanalsobeusedbyinterestedsoftwarepractitioners
whoarenotnecessarilywithinaformalteachingframework.
xii Preface
Weproposetwowaystousethebookinindustrialenvironments.
First, the book can be used for a course which is based on 14 sessions. This
course format fits for organizations that wish to expand their members’ profes-
sionalknowledgebybecomingfamiliarwithagilesoftwaredevelopment,without
necessarily implementing the agile approach. If the course also contains the
development of a software project using the agile approach, which in academia
takesplaceinthestudio,anewsoftwaresystemshouldbedevelopedforlearning
processpurposes,withrespecttowhichthedifferentactivitiesarefacilitated.The
developmentofanewsoftwareprojectshouldbeundertakenwhetherthecourseis
taughttoarealteamortoagroupofpeoplefromdifferentteamsororganization.
Inthecaseofarealteam,thedevelopmentofanotherprojectthantheteam’sreal
project will enable the team not to confuse their current work habits with agile
practices.
Second, for organizations which wish to start implementing agile software
developmentrightawayorinthenearfuture,wesuggestthattheagileapproach
betaughtfirstinashortformatofatwo-dayworkshoptoateamthathasbeen
carefullyselectedtostartthetransitiontoagilesoftwaredevelopmentwithinthe
organization. Chapter 12, Change, elaborates on such a transition process,
explains the motivation and rationale for this intense workshop format, and
outlines the workshop schedule. After the team members have participated in
that workshop, and when the team starts implementing agile software develop-
mentwithitsrealproject,thebookcanbeusedforclarificationsandelaborations.
Inbothcases,aswellasinotherlearningenvironmentsinindustry,theteaching
andlearningprinciplespresentedinthebookcannaturallybeapplied.
Acknowledgments
Wewouldliketothankallthepractitioners,researchers,students,andmangers,
both in academia and in the software industry, who during the past six years
shared with us their professional knowledge, experience, thoughts, and feelings
with respect to agile software development. They all contributed to our under-
standing of the nature of agile software engineering and fostered our shaping of
theapproachpresentedinthisbook.
Contents
1. IntroductiontoAgileSoftwareDevelopment............... 1
1.1 Overview........................................... 1
1.2 Objectives.......................................... 2
1.3 StudyQuestions ..................................... 2
1.4 ThreePerspectivesonSoftwareEngineering............... 3
1.5 TheAgileManifesto .................................. 4
1.5.1 IndividualsandInteractionsoverProcessesandTools.. 5
1.5.2 WorkingSoftwareoverComprehensiveDocumentation 6
1.5.3 CustomerCollaborationoverContractNegotiation.... 7
1.5.4 RespondingtoChangeoverFollowingaPlan ........ 7
1.6 ApplicationofAgileSoftwareDevelopment ............... 8
1.7 DataAboutAgileSoftwareDevelopment ................. 13
1.8 AgileSoftwareDevelopmentinLearningEnvironments...... 15
1.8.1 UniversityCourseStructure ...................... 15
1.8.2 TeachingandLearningPrinciples.................. 15
1.8.3 TheStudioEnvironment......................... 17
1.8.4 TheAcademicCoachRole ....................... 18
1.8.5 OverviewoftheStudioMeetings .................. 19
1.8.6 LaunchingtheProjectDevelopmentintheStudio..... 20
1.9 SummaryandReflectiveQuestions ...................... 23
1.10 Summary........................................... 24
References......................................... 24
2. Teamwork.............................................. 25
2.1 Overview........................................... 25
2.2 Objectives.......................................... 26
2.3 StudyQuestions ..................................... 26
2.4 ARoleSchemeinAgileTeams ......................... 27
2.4.1 RemarksontheImplementationoftheRoleScheme... 31
2.4.2 HumanPerspectiveontheRoleScheme............. 32
2.4.3 UsingtheRoleSchemetoScaleAgileProjects........ 34
2.5 DilemmasinTeamwork ............................... 34
2.6 TeamworkinLearningEnvironments .................... 36
xiv Contents
2.6.1 TeachingandLearningPrinciples.................. 36
2.6.2 RoleActivities................................. 37
2.6.3 StudentEvaluation............................. 40
2.7 ConcludingReflectiveQuestions ........................ 42
2.8 Summary........................................... 42
References......................................... 42
3. CustomersandUsers .................................... 45
3.1 Overview........................................... 45
3.2 Objectives.......................................... 47
3.3 StudyQuestions ..................................... 47
3.4 TheCustomer....................................... 48
3.4.1 CustomerRole................................. 48
3.4.2 CustomerCollaboration ......................... 54
3.5 TheUser........................................... 55
3.5.1 CombiningUCDwithAgileDevelopment ........... 57
3.6 CustomersandUsersinLearningEnvironments............ 61
3.6.1 TeachingandLearningPrinciples.................. 61
3.6.2 CustomerStories............................... 62
3.6.3 CaseStudiesofMetaphorUse..................... 62
3.7 SummaryandReflectiveQuestions ...................... 67
3.8 Summary........................................... 68
References......................................... 68
4. Time ................................................... 71
4.1 Overview........................................... 71
4.2 Objectives.......................................... 72
4.3 StudyQuestions ..................................... 72
4.4 Time-RelatedProblemsinSoftwareProjects............... 73
4.4.1 ListofTime-RelatedProblemsofSoftwareProjects ... 74
4.4.2 CaseStudy4.1.SoftwareOrganizationalSurvey
fromtheTimePerspective ....................... 75
4.5 TightnessofSoftwareDevelopmentMethods .............. 77
4.6 SustainablePace..................................... 79
4.6.1 CaseStudy4.2.AnIterationTimetable
ofanAgileTeam............................... 80
4.7 TimeManagementofAgileProjects ..................... 81
4.7.1 TimeMeasurements ............................ 81
4.7.2 PrioritizingDevelopmentTasks ................... 83
4.8 TimeinLearningEnvironments......................... 86
4.8.1 ThePlanningActivity........................... 86
4.8.2 TeachingandLearningPrinciples.................. 88
4.8.3 Students’ReflectionsonTime-RelatedIssues......... 89
4.8.4 TheAcademicCoach’sPerspective................. 89