为什么产生软Bornin1968,BecauseofSoftwareCrisis(highcosts,slowdelivery,lowquality)什么是软件：ComputerprogramsandassociateddocumentationandConfigurationData程序、相关文档和数据Softwareproductsmaybedevelopedforaparticularcustomerormaybedevelopedforageneralmarket订制和通用什么是软件工程：Softwareengineeringisanengineeringdisciplinewhichisconcernedwithallaspectsofsoftwareproduction（涉及软件所有方面的工程原则）Softwareengineersshouldadoptasystematicandorganisedapproachtotheirworkanduseappropriatetoolsandtechniquesdependingontheproblemtobesolved,thedevelopmentconstraintsandtheresourcesavailable（采用系统方法、工具和管理技术）什么是软件过程AsetofactivitieswhosegoalisthedevelopmentorevolutionofsoftwareGenericactivitiesinallsoftwareprocessesare:Specification、Development、Validation、Evolution软件开发和升级的一系列活动：描述、开发、测试和升级（定义、设计、实现和测试）软件过程模型：Waterfall（瀑布型）Evolutionarydevelopment（进化型）Formaltransformation（形式化型）Integrationfromreusablecomponents（面向复用型）WhatisCASE辅助工具：Softwaresystemswhichareintendedtoprovideautomatedsupportforsoftwareprocessactivities.CASEsystemsareoftenusedformethodsupportUpper-CASE（高端工具）ToolstosupporttheearlyprocessactivitiesofrequirementsanddesignLower-CASE（低端工具）Toolstosupportlateractivitiessuchasprogramming,debuggingandtesting优良软件的特性Maintainability（可维护）Dependability（可信赖）Efficiency（有效）Usability（可用）面临的挑战：Legacysystems（遗留系统）Old,valuablesystemsmustbemaintainedandupdatedHeterogeneity（多样性）SystemsaredistributedandincludeamixofhardwareandsoftwareDelivery（交付）Thereisincreasingpressureforfasterdeliveryofsoftware职业道德professionalresponsibility：Confidentiality（机密）Competence（工作竞争力）Intellectualpropertyrights（知识产权）Computermisuse（计算机滥用）瀑布模型需求定义系统和软件设计编码和单元测试集成和系统测试运行和维护瀑布模型的问题：Inflexiblepartitioningoftheprojectintodistinctstages（僵化的阶段划分）Thismakesitdifficulttorespondtochangingcustomerrequirements（不适应需求变化）Therefore,thismodelisonlyappropriatewhentherequirementsarewell-understood（适用于需求明确的系统）进化开发：Exploratorydevelopment（演化开发）Throw-awayprototyping（抛弃开发）Problems（问题）Lackofprocessvisibility（过程不可见）Systemsareoftenpoorlystructured（系统结构不好）Spec