电政大三下-包-系统分析与设计larmanooad part

ApplyingUMLandPatterns

AnIntroductionto

Object-orientedAnalysis

andDesign

andIterativeDevelopment

PartI-IntroductionChaptersObjectorientedanalysisanddesignIterative,evolutionary,andagileCasestudyTextbook,44回顾：软件工程软件工程定义IEEE：SoftwareEngineeringare（1）“theapplicationofasystematic系统化,disciplined规范化,quantifiable可度量approachtothedevelopment,operation,andmaintenanceofsoftware”;（2）在（1）中所述方法的研究。软件工程知识体系（SWEBOK）以高质量、低成本为目标，研究软件生产的过程模型、方法与工具

★★★软件工程知识体系内涵软件工程领域中的核心知识包括：软件需求（Softwarerequirements）软件设计（Softwaredesign）软件建构（Softwareconstruction）软件测试（Softwaretest）软件维护与更新（Softwaremaintenance）软件配置管理（SoftwareConfigurationManagement,SCM）软件工程管理（SoftwareEngineeringManagement）软件开发过程（SoftwareDevelopmentProcess）软件工程工具与方法（SoftwareEngineeringToolsandmethods）软件质量（SoftwareQuality）高品质程序标准满足客户要求，客户愿意使用良好的设计和代码，便于维护、重用、扩展回顾：waterfallmodel瀑布模型优势：定义了软件开发基本流程创意阶段：描述问题，市场，关键技术等分析阶段：调查问题与需求。。。劣势：1.人力资源问题：--知识技能需求不同--人员数量要求不同2.容错能力问题：--在后期发现需求问题，工作量难接受3.前后依赖问题：--前面需求模糊，后面工作无法开展现象：延期，项目不可控★课程必读彼得·德鲁克（PeterF．Drucker)基本管理问题（知识型团队）重视目标与成果知识的权威（知识工作者即为管理者）时间的管理团队的组织与协作（技能互补团队）组织的目的是使平凡的人做出不平凡的事布鲁克斯(FrederickP.Brooks.Jr.)复杂软件的问题管理问题产品定义问题设计问题前人的经历是后人的财富Chap2

Iterative,Evolutionary,andAgile迭代、敏捷地开发为什么迭代、敏捷开发是OOAD的关键“最佳实践”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（逐步趋向稳定）Effectivemanagementofchangingrequirements（有效管理需求变化）Continuousintegration（持续集成）Earlyunderstandingofthesystem(‘Helloworld!’effect)（尽早接触整个系统）Ongoingriskassessment（在线风险评估）★★IterativeandEvolutionary2IterativeandEvolutionary3IterativeandEvolutionary4★迭代UPvs.Scrum术语AgileIterativeUPScrumIteration（迭代周期）Sprint（冲刺）Usecases（用例）或Story（故事）Backlog（产品条目，特征）Kickoffmeeting（启动会议）SprintplanmeetingWorkshop（工作会议）Dailymeeting（每日例会）Demo（演示）SprintdemoReview&nextPlan（回顾与下个迭代计划）Sprintreview（冲刺回顾）CoffeeTime（私下交流时间）Phase（阶段）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