ApplyingUMLandPatterns

AnIntroductionto

Object-orientedAnalysis

andDesign

andIterativeDevelopment

PartI-IntroductionChaptersObjectorientedanalysisanddesignIterative,evolutionary,andagileCasestudyTextbook,44回顧：軟件工程軟件工程定義IEEE：SoftwareEngineeringare（1）“theapplicationofasystematic系統(tǒng)化,disciplined規(guī)范化,quantifiable可度量approachtothedevelopment,operation,andmaintenanceofsoftware”;（2）在（1）中所述方法的研究。軟件工程知識體系（SWEBOK）以高質(zhì)量、低成本為目標(biāo)，研究軟件生產(chǎn)的過程模型、方法與工具

★★★軟件工程知識體系內(nèi)涵軟件工程領(lǐng)域中的核心知識包括：軟件需求（Softwarerequirements）軟件設(shè)計（Softwaredesign）軟件建構(gòu)（Softwareconstruction）軟件測試（Softwaretest）軟件維護(hù)與更新（Softwaremaintenance）軟件配置管理（SoftwareConfigurationManagement,SCM）軟件工程管理（SoftwareEngineeringManagement）軟件開發(fā)過程（SoftwareDevelopmentProcess）軟件工程工具與方法（SoftwareEngineeringToolsandmethods）軟件質(zhì)量（SoftwareQuality）高品質(zhì)程序標(biāo)準(zhǔn)滿足客戶要求，客戶愿意使用良好的設(shè)計和代碼，便于維護(hù)、重用、擴(kuò)展回顧：waterfallmodel瀑布模型優(yōu)勢：定義了軟件開發(fā)基本流程創(chuàng)意階段：描述問題，市場，關(guān)鍵技術(shù)等分析階段：調(diào)查問題與需求。。。劣勢：1.人力資源問題：--知識技能需求不同--人員數(shù)量要求不同2.容錯能力問題：--在后期發(fā)現(xiàn)需求問題，工作量難接受3.前后依賴問題：--前面需求模糊，后面工作無法開展現(xiàn)象：延期，項目不可控★課程必讀彼得·德魯克（PeterF．Drucker)基本管理問題（知識型團(tuán)隊）重視目標(biāo)與成果知識的權(quán)威（知識工作者即為管理者）時間的管理團(tuán)隊的組織與協(xié)作（技能互補(bǔ)團(tuán)隊）組織的目的是使平凡的人做出不平凡的事布魯克斯(FrederickP.Brooks.Jr.)復(fù)雜軟件的問題管理問題產(chǎn)品定義問題設(shè)計問題前人的經(jīng)歷是后人的財富Chap2

Iterative,Evolutionary,andAgile迭代、敏捷地開發(fā)為什么迭代、敏捷開發(fā)是OOAD的關(guān)鍵“最佳實踐”UnifiedProcessTheUnifiedProcess(UP)representsamainstreamapproachforsoftwaredevelopmentacrossthespectrumofprojectscales.Theprocessisscalable:youneednotusetheentireframeworkoftheprocessforeveryproject,onlythosethatareeffective.Theprocessiseffective:ithasbeensuccessfullyemployedonalargepopulationofprojects.Improvesproductivitythroughuseofpracticalmethodsthatyou’veprobablyusedalready(butdidn’tknowit).Iterativeandincrementalapproachallowsstartofworkwithplete,imperfectknowledge.★UnifiedProcessWorkflowsWorkflowsdefineasetofactivitiesthatareperformedWorkflowscutacrossthephases,butwithdifferentlevelsofemphasisineachphaseThecoreworkflowsBusinessModelingRequirementsanalysisDesignImplementationTestandIntegration★★TheCoreWorkflows1BusinessModelingDevelopandrefinetheproblemdefinitionIdentifystakeholderneedsDefinesystemfeaturestobeconsideredDefinethesystemscopeBuildtheuse-casemodelRequirementsAnalysisRefineuse-casemodelDefinethedomainmodelDefineacandidatearchitecture(transitionstodesign)Refinethearchitecture(transitionstodesign)TheCoreWorkflows2DesignDesignthephysicalrealizationsoftheusecasesDevelopthedesignmodelDevelopthedeploymentmodelImplementationPlansubsystemimplementationImplementcomponents:classes,objects,etc.Performunit-leveltestingPerformcomponentandsystemintegrationTestandIntegrationBuildthetestmodel:testcasesandexpectedresultsPlan,design,implement,execute,andevaluatetestsUseCaseDrivenUsecaseAproserepresentationofasequenceofactionsActionsareperformedbyoneormoreactors

(humanornon-human)andthesystemitselfTheseactionsleadtovaluableresultsforoneormoreoftheactors—helpingtheactorstoachievetheirgoalsUsecasesareexpressedfromtheperspectiveoftheusers,innaturallanguage,andshouldbeunderstandablebyallstakeholdersUse-case-drivenmeansthedevelopmentteamemploystheusecasesfromrequirementsgatheringthroughcodeandtest★★ArchitectureCentricSoftwarearchitecturecapturesdecisionsabout:TheoverallstructureofthesoftwaresystemThestructuralelementsofthesystemandtheirinterfacesThecollaborationsamongthesestructuralelementsandtheirexpectedbehaviorArchitecture-centric:softwarearchitectureprovidesthecentralpointaroundwhichallotherdevelopmentevolvesProvidesa‘bigpicture’ofthesystemProvidesanorganizationalframeworkfordevelopment,evolvingthesystembyattendingtomodifiabilityqualitiesofthesystemFacilitatesreuse★★IterativeandEvolutionary1Aniterativeandevolutionaryapproachallowsstartofdevelopmentwithplete,imperfectknowledgeIterativeandevolutionarythefollowingadvantages:Logicalprogresstowardarobustarchitecture（逐步趨向穩(wěn)定）Effectivemanagementofchangingrequirements（有效管理需求變化）Continuousintegration（持續(xù)集成）Earlyunderstandingofthesystem(‘Helloworld!’effect)（盡早接觸整個系統(tǒng)）Ongoingriskassessment（在線風(fēng)險評估）★★IterativeandEvolutionary2IterativeandEvolutionary3IterativeandEvolutionary4★迭代UPvs.Scrum術(shù)語AgileIterativeUPScrumIteration（迭代周期）Sprint（沖刺）Usecases（用例）或Story（故事）Backlog（產(chǎn)品條目，特征）Kickoffmeeting（啟動會議）SprintplanmeetingWorkshop（工作會議）Dailymeeting（每日例會）Demo（演示）SprintdemoReview&nextPlan（回顧與下個迭代計劃）Sprintreview（沖刺回顧）CoffeeTime（私下交流時間）Phase（階段）Disciplines（科目）Milestone（里程碑）AgileMethodsandAttitudesAgileMethods:However,shorttimeboxediterationswithevolutionaryrefinementofplans,requirements,anddesignOther:simplicity,lightness,communication,self-organizingteams,etc.Scrum,XP……TheAgileManifestoIndividualsandinteractionsoverprocessesandtoolsWorkingsoftwareovercomprehensivedocumentationCustomercollaborationovercontractnegotiationRespondingtochangeoverfollowingaplan★AgileMethodsandAttitudesTheAgilePrinciplesOurhighestpriorityistosatisfythecustomerthroughearlyandcontinuousdeliveryofvaluablesoftware.echangingrequirements,evenlateindevelopment.Deliverworkingsoftwarefrequently.Businesspeopleanddevelopersmustworktogetherdailythroughouttheproject.Buildprojectsaroundmotivatedindividuals.Face-to-faceconversation.Workingsoftwareistheprimarymeasureofprogress.Agileprocessespromotesustainabledevelopment.Thesponsors,developers,andusersshouldbeabletomaintainaconstantpaceindefinitely.Continuousattentiontotechnicalexcellenceandgooddesignenhancesagility.Simplicity-theartofmaximizingtheamountofworknotdoneisessential.Thebestarchitectures,requirements,anddesignsemergefromself-organizingteams.Atregularintervals,theteamreflectsonhowtoemoreeffective,thentunesandadjustsitsbehavioraccordingly.★AgileModelingAdoptinganagilemethoddoesnotmeanavoidinganymodelingThepurposeofmodelingandmodelsisprimarilytosupportunderstandingandcommunication,notdocumentation.Don'tmodelorapplytheUMLtoallormostofthesoftwaredesign.Usethesimplesttoolpossible.Don'tmodelalone,modelinpairs(ortriads)atthewhiteboard.Createmodelsinparallel.Use"goodenough"simplenotationwhilesketchingwithapenonwhiteboards.Knowthatallmodelswillbeinaccurate,andthefinalcodeordesigndifferentsometimesdramaticallydifferentthanthemodel.DevelopersthemselvesshoulddotheOOdesignmodeling,forthemselves.★UnifiedProcessPhases1★UnifiedProcessPhases2CoreWorkflowsandPhases1CoreWorkflowsandPhases2CoreWorkflowsandPhases3Artifacts,Workers,andActivities1Anartifactisapieceofinformationthatisusedasinputto,changedby,oroutputfromaprocessExamplesinclude:Models—use-case,domain,anddesignModelelements—usecase,domainclass,designclassDiagramsanddocumentsSourcecodeExecutableelements★Artifacts,Workers,andActivities2WorkersdefinethebehaviorandresponsibilitiesofanindividualorateamExamples:Architect,use-caseengineer,componentengineer,systemintegratorSomeimportantdistinctions:WorkersparticipateinthedevelopmentofthesystemActorsareoutsidethesystemandhaveusagerelationshipswiththesystemStakeholderspassbothactorsandworkers,aswellasothersinvolvedwiththeproject★Artifacts,Workers,andActivities3ActivitiesarethetasksperformedwithinaworkflowActivitiescandescribeawiderangeofabstractionlevels,fromhigh-level(‘constructdomainmodel’)tolow-level(‘implementclass’)Examplesinclude:PlaniterationFindusecasesandactorsExecuteintegrationtestReviewtestresultsTheAgileUnifiedProcessTheUnifiedProcesshasbeendesignedfromtheoutsetas:Lightweight:‘Payasyougo.’Useonlytheparts