《复习材料软工 review全》由会员分享，可在线阅读，更多相关《复习材料软工 review全（41页珍藏版）》请在金锄头文库上搜索。
1、 1 掌握软件生命周期的几个活动。 （CH4） 目标 任务 输出 Requirements AnalysisDesignImplementationTestingMaintaining Requirements Analysis Requirements Engineering （Analyst） 目的： 描述明确的问题域特性 E; 定义良好的系统行为 S ; 预期的需求 R 需求工程的目的就是根据 E，构建 S，使得 需求工程的困难之处： （1）不存在描述明确的 E； （2）不存在确定的针对 S 的评估标准 R； （3） 是一个创造性的过程。 需求工程的主要工作 研究问题背景，描述问题域特性
2、 E 需求开发,确定 R 构建解系统，描述解系统行为 S，使得 理解现实为第一目的，保证 S 的质量为第二目的 Mainly Result : SRS (Software Requirements Specification) Design（Architect 、Designer） Aim: establishing software structures based on software entities, that is a model of the whole system to be developed（基于软件的主题建立软件架构，开发整 个系统的模型） Tasks of Desig
3、n Architecture Design（Architect） The definition of the global architecture of the system Detail (System) Design（Designer） System is decomposed in components Definition of component functionalities Definition of component interfaces HCI Design（人机交互设计） （Designer） Making interfaces usability Design dec
4、isions dramatically impact system quality Alternatives, tradeoff Mainly Result Model architecture model, System model Specification Architecture specification, system component specification, HIC documents Implementation（Programmer） RSE, RSE, Aim: implementation of individual components in a program
5、ming language（使 用一种编程语言实现每个相对独立的系统组件） It starts from the component specifications developed during design Interfaces defined in the design should be respected by the implementation of the component Tasks Program design Code should be well documented and easy to read, flexible, correct and reliable P
6、rogramming Debug Result should be an executable program Testing（Tester） Aim: validating and verifying the qualities of software products（确认并检验产 品质量） Tasks Testing design Unit testing: verification of component implementations against their interfaces Integration testing: verification of component in
7、tegration against system architecture System testing: validation of the extent to which the requirements specification is fulfilled Testing does not necessarily follow the implementation phase Testing and implementation may run in parallel Testing may even affect the requirements analysis phase, whe
8、re test cases may be derived directly from the requirements specification Testing result: errors and faults Installing and Maintenance（Trainer 、Supporter） Aim: keeping the system operational after delivery to the customer Corrective : identification and removal of faults Adaptive: modifications need
9、ed to achieve interoperability with other systems Perfective: incorporation of new features, improved performance and other modifications to increase customer satisfaction Preventive: modifications to mitigate possible degradation of usability, maintainability, etc. Tasks Installing, training, maint
10、enance The maintenance phase needs to be considered part of the development process Even though the activities within maintenance are requirements analysis, design, implementation and testing 2 软件生命周期和过程模型（CH4） 特征描述 优点 缺点 Build and Fix Model Properties No planning or analysis The working program is
11、the only work product Advantage Appropriate for small programs written by one person Disadvantage Understandability and maintainability decrease rapidly with increasing program size Totally unsatisfactory Need a life-cycle model Waterfall Model（瀑布模型，又称经典生命周期）（瀑布模型，又称经典生命周期） Characterized by Sequenti
12、al steps (phases) Feedback loops (between two phases in development) Documentation-driven（文档驱动）其他驱动：风险驱动、需求 驱动、质量驱动 Advantages Documentation and clearly defined phases Disadvantages Complete and frozen specification document up-front often not feasible in practice（不符合现实应用） Customer involvement in th
13、e first phase only（缺少用户参与） Sequential and complete execution of phases often not desirable The product becomes available very late in the process（最后阶段 才产生结果） Applicability Only appropriate when the requirements are well-understood Iterative Models（迭代模型）（迭代模型） Build software in multiple iterations（多次
14、进行） Two flavors Incremental（增量过程模型） Incremental Delivery（增量模型） Evolutionary（演化过程模型） Prototyping（原型开发） Spiral Model（螺旋模型） Incremental Delivery（增量模型） 需求驱动 以迭代的方式运用瀑布模型 随着时间的推移，增量模型在每个阶段运用线性序列。每个线性序列生产出一个软 件的可交付增量。如，采用增量模型开发的字处理软件，在第一个增量中提供基本 文件管理、 编辑和文档生成功能； 在第二个增量中提供复杂的编辑和文档生成功能； 第三个（P38） User requir
15、ements are prioritized and the highest priority requirements are included in early increments Each release adds more functionality, i.e., a new increment The waterfall model is employed in each phase Advantages 优点优点: Operational quality portion of product within weeks Smaller capital outlay, rapid return on investment Comprehensive spec up front can be used as a contract Disadvantage 缺点缺点: May be hard to create a comprehensive （ 全 面 的 ） requirements spec（说明书） up front（预先） if a domain not well understood Prototyping（原型开发）/可以作为一个独立的过程模型，更多的作为一种技术，当需求模 糊的时候，帮助软件工程师和
