软工知识总结.docVIP

软件工程知识总结 软件生命周期 知识点：各阶段名称、顺序、任务 软件生命周期 定义时期 基本任务是：确定软件开发工程的总目标；研究该项目的可行性；分析确定客户对软件产品的需求；估算完成该项目所需的资源和成本，并且制定工程进度表。这个时期的工作称为系统分析，由系统分析员负责完成。 开发时期 基本任务是：具体设计和实现在前一个时期定义的软件，软件开发时期它通常由下述4个阶段组成：总体设计(又称为概要设计、结构设计)；详细设计；编码和单元测试；综合测试。其中前两个阶段又称为系统设计，后两个阶段又称为系统实现。由系统设计员和编程人员、测试人员负责完成。 软件维护时期 基本任务是：对交付使用的系统进行升级和后期维护管理，由系统维护员负责完成。 Chapter 1软件和软件工程 1 what is software? Software’s Dual Role （软件的双重角色）Software is a product：Delivers computing potential ，Produces, manages, acquires,modifies, displays, or transmits information Software is a vehicle for delivering a product：Controls other programs ；Effects communications ；Helps build other software What is Software? Software is a set of items or objects that form a “configuration” that includes： Instructions or computer programs that when executed provide desired function and performance; Data structures that enable the programs to adequately manipulate information; Documents that describe the operation and use of the programs. Software Characteristics (软件的特点) Software is logical but not physical. It is developed or engineered, it is not manufactured in the classical sense. Software doesn’t “wear out”, but it does deteriorate. Software is complex and custom-built Category of Software：system software；application software 2. Software Crisis Software crisis –chronic affliction A set of problems that are encountered in the software development Regardless of what we call it, the set of problems that are encountered in the development of computer software is not limited to software that doesnt function properly. Rather, the affliction encompasses problems associated with how we develop software, how we support a growing volume of existing software, and how we can expect to keep pace with a growing demand for more software. WHY? （1）与软件本身的特点有关 缺乏“可见性” 软件较难维护。 为了在预定时间内开发出规模庞大的软件，必须由许多人分工合作，然而，如何保证每个人完成的工作合在一起确实能构成一个高质量的大型软件系统，不仅涉及许多技术问题，更重要的是必须有严格而科学的管理。2）与软件开发与维护的方法不正确有关 忽视软件需求分析的重要性轻视维护 用现代工程的概念、原理、技术和方法进