Web Engineering

Inlessthanadecadeofexistence,theWebhasreachedatrulystaggeringstage, demonstratedbythescope,thereach,andthesizeofWeb-basedapplications andactivities. Concentratinginitiallyoninformationdissemination,thescopeof theapplicationsisnowlimitedonlybyourimagination. Thereachisconstantly expandingandsoarethenumberandsizeoftheapplications,alongwiththe underlyingcomplexity,rangeofpurposes,andthetimeneededtodevelopand maintainthem. Atthesametime,thedevelopmentandmaintenanceprocesses ofWebapplicationshavenotprogressedatasu?cientlyrapidpacetomeetthese challengesanddemands. Consequently,thelikelihoodisthatWebapplication developmentwillgetintoacrisisanditisnothardtoimaginethatthiswould dwarfthe‘softwarecrisis’identi?edlongagointhe1960s. WebEngineeringaimstoavertthispotentialcrisisbygeneratingaproactive approachtothesuccessfuldevelopmentofWeb-basedsystemsandapplications. WebEngineeringinvolvestheuseofscienti?c,engineering,andmanagement principlesandsystematicapproacheswiththeaimofsuccessfullydeveloping, deploying,andmaintaininghighqualityWeb-basedsystemsandapplications. WebEngineering,initscurrentform,isanearlyattempttoidentifythes- ni?cantissuesandproblems,andtheirsolutions,indevelopingWeb-basedapp- cations. Asweseeit,WebEngineeringisnotyetestablishedasafulldiscipline norhasitdevelopedanidenti?ableorstableform,sinceeverythingconnected withtheWebisstillinastateof?ux. Oneonlyhastolookatthenumberof variedactivitiesthattheWorldWideWebConsortiumisengagedintorealise thatastableWebenvironment,andhenceprovenmethodsfordevelopmental activitiesbasedontheWeb,isstillsomedistanceaway. OurearlyforaysintotheWebarena,withtheconstantexcitementofnew developmentsandchallenges,forcefullybroughttomindourentryintothec- puting?eld,almostthreedecadesago. Atthattime,comparedtowhatthe technologycoulddo,oure?ortsincomputerizingpayrollandaccountingapp- cationsinrealityseemedpunyanddisappointing. TheWeb,ontheotherhand, didnotseemshackled,inawaythatearlycomputingwas,tothesebure- craticandunimaginativewaysofconductinghumanandorganizationala?airs. Itseemedthattheorganizational,spatial,andphysicalconstraintswereabout toloosen,ifnotdisappear,altogether. Andyet,whenwelookedaroundatthewayWebsitesandapplicationswere beingdeveloped,itseemedtousthattheearlypatternofhaphazarddev- opment,minimaltesting,andlackofattentiontothemaintenanceissuesthat characterisedthe‘softwarecrisis’werestillverymuchwithus. Itwasasthough the‘newgeneration’insistedonmakingthesamemistakesasitsparents! Thisfeelingofd´ej`avuledustoquestionthenatureofWeb-basedandW- relatedactivities. Ofcourse,wewerenotalone,aswesoondiscovered. The resultiswhatisbeingcalledWebEngineeringwhichhadits?rstintroduction inaworkshopattheSeventhWorldWideWeb(WWW7)conferenceinBrisbane in1998. IthasnowbecomeaserieswithmoreworkshopsatWWW8(Toronto, VI Preface 1999)andWWW9(Amsterdam,2000),andalsoattheInternationalConference onSoftwareEngineering(ICSE99)in1999inLosAngelesandICSE2000in Limerick,Ireland. AnotherworkshopisscheduledforWWW10inHongKong inMay2001. Themainpurposebehindtheseworkshopshasbeentoshareandpoolthe collectiveexperienceofpeople,bothacademicsandpractitioners,whoare- tivelyworkingonWeb-basedsystems. Theworkshopshavegenerallyconsisted ofkeynoteaddresses,peer-reviewedcontributedpapers,andsessionsofopen discussions. About This Book Inthisvolume,weprovideaconsolidatedviewofrecentwork,highlightingdev- opmentsandadvancesintheareaofWebEngineering. Thisselectionofpapers drawsmainlyfromthelastthreeworkshops,heldinconjunctionwithICSE1999, WWW9,andICSE2000. Wealsopresentalistofadditional,usefulresourceson WebEngineeringsuchasbooks,specialissues,articles,andWebsites. Ouraim istoprovideabookthatwillbeaconvenientandusefulreferencetoallthe researchers,practitioners,andstudentsinterestedinWebapplicationdevel- ment. WebEngineeringtakesitsinspirationfromSoftwareEngineering. Atthe sametime,itisalsoanexplicitacknowledgementofthemulti-dimensionalnature ofWebapplications,encompassingtechnicalcomputing,informationstruct- ing,navigationandmanagement,networkperformanceandsecurity,legaland socialissues,graphicdesign,multiplicityofuserpro?les,andthevariedope- tionalenvironments. Accordingly,thepapersinthisvolumecoverperspectives onWebEngineering,navigationandadaptivity,designaspects,acceptancec- teriaforWeb-basedsystems,developmentandmanagementofWebsitesand Web-basedapplications,Webmetrics,andcasestudies. Forconvenience,thepapersareorganizedin?vesections:1)Introduction andPerspectives,2)ManagingInformationontheWeb,3)Web-BasedSystems Development,4)DesignforPerformance,WebMetrics,andTesting,and5) WebMaintenanceandReuse. Intheirownways,allthepapersareforwa- looking,tryingtoanticipateproblems,creatingtools,experimentinginnovel ways,wideningtheareasofapplications,andre-examiningparadigms. Inother words,thepapersrepresentasharedattitudeofbeinginclusiveratherthan focusingnarrowly. WebEngineeringisaforwardlookingandcollaborativediscipline. The- persinthiscompendium,takenindividually,representonlythetipoftheiceberg ofworldwideWebdevelopment. Together,theymakeasigni?cantcontribution totheevolutionofamoresystematicapproachtoWebdevelopment. Thec- pendiumhasbeenmadepossiblebythemanypeoplewhosharetheseviews. We hopethereaderswilljoinusintheseendeavors. January2001 SanMurugesan YogeshDeshpande Table of Contents WebEngineering:IntroductionandPerspectives WebEngineering:IntroductionandPerspectives–Overview. . . . . . . . . . . . . . . . 1 WebEngineering:ANewDisciplineforDevelopment ofWeb-BasedSystems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 SanMurugesan,YogeshDeshpande,SteveHansenandAthulaGinige WebEngineering:BeyondCS,ISandSEEvolutionary andNon-engineeringPerspectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 YogeshDeshpande,SanMurugesanandSteveHansen WebEngineeringinAction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 AthulaGinige Web-BasedSystemsDevelopment:Processand Methodology Web-BasedSystemsDevelopment:ProcessandMethodology–Overview. . . 33 CorporateWebDevelopment: FromProcessInfancytoMaturity–ACaseStudy. . . . . . . . . . . . . . . . . . . . . . . . . 36 YogeshDeshpandeandAthulaGinige ApplyingCross-FunctionalEvolutionaryMethodologies toWebDevelopment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 KennethS. Norton DevelopmentandEvolutionofWeb-Applications UsingtheWebCompositionProcessModel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 MartinGaedkeandGuntramGraf ¨ EngineeringtheWebforMultimedia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 SavithaSrinivasan,DulcePonceleon,ArnonAmir,BrianBlanchard andDragutinPetkovic ModellingSecurityPoliciesinHypermediaandWeb-BasedApplications. . . . 90 PalomaD´?az,IgnacioAedoandFivosPanetsos Web-BasedInformationSystemsDevelopment– AUserCenteredEngineeringApproach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 ChristopheGnaho RapidServiceDevelopment:AnIntegralApproach toe-BusinessEngineering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 WilJanssenandMaartenSteen VIII Table of Contents ManagingInformationontheWeb ManagingInformationontheWeb–Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Layout,ContentandLogicSeparationinWebEngineering. . . . . . . . . . . . . . . . 135 ClemensKererandEnginKirda RestrainingContentExplosionvs. ConstrainingContentGrowth. . . . . . . . . . 148 FranciscoJ. Monaco,AdilsonGonzagaandLeonardoB. Guerreiro AClassi?cationofWebAdaptivity:TailoringContentand NavigationalSystemsofAdvancedWebApplications. . . . . . . . . . . . . . . . . . . . . 156 ArnoScharl WebEngineering:TheDevelopers’ViewandaPractitioner’sApproach. . . 170 SotirisP. Christodoulou,ParisA. Za?risandTheodoreS. Papatheodorou DevelopmentTools,SkillsandCaseStudies DevelopmentTools,SkillsandCaseStudies–Overview. . . . . . . . . . . . . . . . . . . 188 SynthesisofWebSitesfromHighLevelDescriptions. . . . . . . . . . . . . . . . . . . . . . 190 Joao ˜ M. B. CavalcantiandDavidRobertson Meta-XMLSpeci?cation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 StephenC. ArnoldandLeoMark EngineeringofTwoWeb-EnabledCommercialSoftwareServices. . . . . . . . . . 213 SiddharthaR. Dalal,AshishJain,NachimuthuKarunanithi, GardnerPattonandManishRathi ASkillsHierarchyforWeb-BasedSystemsDevelopment. . . . . . . . . . . . . . . . . . 223 SteveHansen,YogeshDeshpandeandSanMurugusan ACaseStudyofaWeb-BasedTimetablingSystem. . . . . . . . . . . . . . . . . . . . . . . 236 ShuWingChanandWeigangZhao Performance, TestingandWebMetrics Performance,TestingandWebMetrics–Overview. . . . . . . . . . . . . . . . . . . . . . . 245 EngineeringHighlyAccessedWebSitesforPerformance. . . . . . . . . . . . . . . . . . 247 JimChallenger,ArunIyengar,PaulDantzig,DanielDias andNathanielMills SpecifyingQualityCharacteristicsandAttributesforWebsites. . . . . . . . . . . . 266 LuisOlsina,GuillermoLafuenteandGustavoRossi AFrameworkforDe?ningAcceptanceCriteria forWebDevelopmentProjects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 DavidLowe Table of Contents IX MeasurementandE?ortPredictionforWebApplications. . . . . . . . . . . . . . . . .