软件工程 实践者的研究方法 PPT

1、Computing and SE IIIntroduction and OverviewEr-Yu Ding2009-9Software Institute, NJURecommend papernProspects for an engineering discipline of softwaren what knowledge is important to a software professional Main Contents1.Introduction2.What is software?3.What is SE (Software Engineering)？4.SE .vs. C

2、S (Computer Science)?5.Contents of SE6.How to learn SE?丁二玉925E83621362-925You should learned beforen计算系统基础q硬件初步（计算机体系结构）q系统软件初步（操作系统、编译）qC语言（结构化程序设计）n计算与软件工程IqJava语言（面向对象程序设计）q基本的面向对象思想q软件工程初步？n离散数学Till now you cannProgrammingqWith c or javanKeywordsnSyntaxnSemanticqUsing the abstract software entit

3、iesnInstructionnStatementnFunctionsnModulenObjectnObject-OrientedqInherit, Encapsulation, PolymorphismThis is Software Engineering ?This is only Programming!Objectives of this coursenBasics of Software EngineeringqBased on your capability of programmingqBase on the knowledge you have learnednabstrac

4、t software entitiesqFunctions/Object/Module/Object-OrientedqDo Software, not ProgramnAnalysis, Design and CreativityqBehavior in engineering manner, not a hero!nEngineering ideanTeamworknMonitor and controlCourse overviewn目标，通过本课程的学习，学生应该能够：q掌握软件工程的基本思想、方法和技术，了解软件工程发展历史，理解软件生命周期的各个阶段和各种软件开发模型；q建立工程观

5、，了解软件工程的专业范畴，掌握有关职业技能，理解软件开发的“工程性”；q能够选择合适的系统开发方法，规划一个中等规模软件系统的开发过程；q理解结构化方法和面向对象方法。掌握基本的结构化或面向对象的分析与设计技术，能够为一个中等规模系统创建高质量的ERD、DFD、结构图、UML用例图、类图、顺序图、状态图和构件图。并初步理解软件工程的复杂性，能够为较复杂问题提供合理的解决方案，包括问题分析、基本的体系结构构建和设计方案折中与选择q理解软件质量保障方法，包括软件评审和软件测试的基本方法，能够完成中等规模系统的质量保障；q理解软件项目管理思想，能够为开发一个中等规模系统作出规划，能够对中等规模软件系

6、统的开发进度进行度量和追踪；q利用软件工程方法提高程序设计技能，树立在宏观软件工程方法下展开程序设计的理念和习惯Course overviewn教学内容包括：q软件的工程基础q软件工程的专业范畴q软件工程的发展历史和从业知识。q软件需求基础q软件设计基础q软件构造基础q软件质量基础q软件演化基础q软件项目管理基础Course overviewn资料q教材n课件n软件工程实践者的研究方法q参考资料nIan Sommerville，软件工程（原书第8版），机械工业出版社nShari Lawrence Pfleeger，Joanne M.Atlee，软件工程（第3版），人民邮电出版社n软件工程课程网

7、站：/jsalvage/Summer2007/CS451/index.htmln软件工程课程网站：/turgut/COURSES/EEL6883_SEII_Spr07/ EEL6883_SEII_Spr07_LectureSlides.htmln软件工程经典论文推荐：http:/www.inf.ed.ac.uk/teaching/courses/seoc1/2005_2006/resources/Course overviewn考核q作业n10q实验n工作簿管理n40%q期末考试n50课程要求n课前预习n课堂

8、q认真听讲q做好笔记n作业q独立完成q准时提交n晚提交的：1天扣10；3天扣30；一周扣50；一周0分q雷同者取消课程成绩n课外q复习q分层次拓展n考试q严格要求Main Contents1.Introduction2.What is software?3.What is SE (Software Engineering)？4.SE .vs. CS (Computer Science)?5.Contents of SE6.How to learn SE?2. What is software?Your thoughts here!？SoftwarenIn the first, software

9、 is not separated qBefore 1960sinstructionMachineSoftwarenWhen software is produced, it are toolsqSoftware = programs + documents + data+CodeSoftwarenAbout now, software is simulation more than toolqKnowledge is carried on software qSoftware = programs + documents + data + knowledgeknowledgeSolution

10、s=organization of software entitiesProgram (Code)Application (Real World )CentricKnowledge Centric Need to find Need to process Need teamwork Will changing the worldTasks of software developmentnAll software construction involves essential tasks, the fashioning of the complex conceptual structures t

11、hat compose the abstract software entityqAnalysis, Design and CreativitynAnd accidental tasks, the representation of these abstract entities in programming languages and the mapping of these onto machine languages within space and speed constraints.-Frederick P. Brooks, Jr., No Silver Bullet, 1986Ma

12、in Contents1.Introduction2.What is software?3.What is SE (Software Engineering)？4.SE .vs. CS (Computer Science)?5.Contents of SE6.How to learn SE?Software is much more complex than ProgramnAs simulation of the world, software must simulative to the real world mostly and can solve problems of the rea

13、l worldnThe real world is complexnSo qSoftware is complexnProblems are complexnSolutions are complexqOnly programmers cant deal with software development wellnThey dont know the problems and solutionsnAnd none can tell them the knowledge clearlyqIf we still produce software only with programming, ba

14、dly things will happen.Software needed to be engineeredn1968年北大西洋公约组织的计算机科学家在联邦德国召开的国际学术会议上第一次提出了“软件危机”(software crisis)这个名词q软件危机: 指的是在计算机软件的开发和维护过程中所遇到的一系列严重问题n开发成本超出预算，实际进度比预定计划一再拖延。n用户对“已完成”系统不满意的现象经常发生。n件产品的质量往往靠不住。Bug一大堆，Patch一个接一个。n件的可维护程度非常之低。n软件通常没有适当的文档资料。n软件的成本不断提高。n软件开发生产率的提高赶不上硬件的发展和人们需求

15、的增长n1969年的后续会议中提出了“软件工程”的发展之路Software engineering is about managing the complexity!3. What is SE ？Your thoughts here!？What is Software Engineering?nAs defined in IEEE Standard 610.12:q（1）The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenanc

16、e of software; that is, the application of engineering to software.q（2）The study of approaches as in （1）q（1）应用系统化的、学科化的、定量的方法，来开发、运行和维护软件，即，将工程应用到软件。q（2）对（1）中各种方法的研究。EngineeringnExamplesqMechanical engineeringqArchitectural engineeringqChemical engineeringqElectrical engineeringqNuclear engineeringq

17、nYours thoughts hereqWhat is the word “Engineering” means?What is the “Engineering” means?nEngineering is qThe application of scientific principles and methods to the construction of useful structures & machines which can solve some problems of the real worldqCreating cost-effective solutions to pra

18、ctical problems by applying scientific knowledge to building things in the service of mankindFactors of EngineeringnProblem: MotivationnScientific Knowledge: InstrumentnSolution/Machine: ObjectivenCost-Benefit Effective: Condition Software engineeringnProblemqReal world chaosnIf the state of the rea

19、l world do not accord with our expectations , then there is a problem.qBroad scopenAll fields that mankind set foot innIn others engineering, problems are limitedqMostly not clear, needed to be discoverednIn others engineering, problems are specific and clearqEngineering IdeanObjectives (Know what y

20、ou want to)nCan software engineer master so much knowledge?qAs a software engineer, communication and negotiation skill is very importantqCollaborating with all kinds of people, especially users.qTeamworkTeamworknAbout SE professional qSystems Analyst - to find whats the problem and the direction th

21、e solutionqSoftware Architect give solution a overall structure for the problemqSoftware Designer design the solution detail structureqSoftware Programmer implements the design using software development toolsqSoftware Tester (independent verification and validation e.g. NASA IV&V Facility, South Fa

22、irmont)qSoftware Project Manager Coordinator, Monitor and controllernplan, organize, direct, coordinate, control a software project (emphasis on risk management)TeamworknAbout SE professional(cont.)qSoftware Configuration Manager identify, change control, status accounting, audits and reviewsqSoftwa

23、re Quality Manager/Engineer software reliability modeling, statistical quality control, defect analysisqSoftware Network Specialist LAN/WAN Network design, installation, maintenanceqSoftware Systems Administrator administers user accounts, technology refreshment, software deployment to users, softwa

24、re problem solversqSoftware Database Administrator administers the database (installation, maintenance, backup, refreshment)qSoftware engineeringnScientific KnowledgeqComputing science as the scientific basisnFormal techniquesqBased on mathematics and logicqMany aspects have been made systematicnMet

25、hods/methodologies/techniquesnLanguagesnToolsnProcessesSoftware engineeringnScientific KnowledgeqScience .vs. PracticenFormalists: base their work on the theoretical foundations of computing sciencenPragmatists: take that software engineering is a practical discipline that can be benefit from more t

26、han formal techniquesqEngineering IdeanScience + Principle + ArtSoftware engineeringnScience + Principle + ArtqScience-Computing science knowledge is basis of SEnFeatures of the computernSoftware entities (program languages)nMethods/methodologies/techniquesnqPrinciple-Practice knowledge should also

27、be effective sharednMethods/techniquesnProblems/solutionsnqArtnCreativitySoftware engineeringnSolution/MachineqVirtual Machine=General machine + Specific solutionnSolution can be mapped into the general machine with the help of program languagesnNot different machines for different problems, like ot

28、hers engineeringqDevelopment of solution is the essential task of SEqMapping solution into general machine is accidental task of SESoftware engineeringnDo the solution work?qEngineering Idea nTradeoffqMonitor and Control Technology churnPerformanceThroughputCapacityAvailabilitySafetyFault toleranceF

29、unctionalityCostCompatibilityResilienceSoftware engineeringnCost-Benefit EffectiveqFeasibility studynBenefit is up to clientsnCost is up to software engineerqThere are always many ways to a destination, software engineers should choose the most cost-benefit effective one (not the most advanced one).

30、qWhen cost-benefit is inessential, then SE may disappearsnCost is smallqSmall programnBenefit is implicitqExploration studynCost is inessentialqComputer science studyqEngineering IdeanCost Benefit EffectiveqMonitor and ControlMain Contents1.Introduction2.What is software?3.What is SE (Software Engin

31、eering)？4.SE .vs. CS (Computer Science)?5.Contents of SE6.How to learn SE?4. SE .vs. CS ?应用软件编译器数据库管理系统网络系统操作系统硬件Virtual MachineMake real world better with itUsing it betterMake it more powerMake it more easier to UseComputer ScientistSoftware EngineeringWhat is the difference between software engin

32、eering and computer science?Computer ScienceSoftware Engineeringis concerned withComputer science theories are currently insufficient to act as a complete underpinning for software engineering, BUT it is a foundation for practical aspects of software engineering theory fundamentalsthe practicalities

33、 of developingdelivering useful softwareScientist vs EngineernComputer Scientistq Proves theorems about algorithms, designs languages, defines knowledge representation schemesqHas infinite timenSoftware EngineerqDevelops a solution for an application-specific problem for a clientqUses computers & la

34、nguages, tools, techniques and methodsqWorks in multiple application domainsqHas limited time (maybe only 3 months.)qwhile changes occurs in requirements and available technologyAnother comparison:Software Engineering VS System EngineeringnWhat is a system?qSome part of reality that can be observed

35、to interact with its environmentqSeparated from its environment by a boundaryqA system receives inputs from the environment & send outputs to the environmentqSystems have interesting emergent propertiesAnother comparison:Software Engineering VS System EngineeringnInformation Systems qSoftware intens

36、ive systems exist to support Human ActivitynSystem Engineering qDesigning, implementing, deploying and operating information systems which include hardware, software and peoplenSoftware engineeringnHardware engineeringnPeople engineeringMain Contents1.Introduction2.What is software?3.What is SE (Software Engineering)？4.SE .vs. CS (Computer Science)?5.Contents of SE6.How to learn SE?5. Contents of SEnSoftware technologiesqTechnologies to produce