《软件工程-实践者的研究方法》chapter-13-cn-软件质量保证

第十三章软件质量保证SlideSettoaccompany

SoftwareEngineering:APractitioner’sApproach,7/e

byRogerS.PressmanSlidescopyright©1996,2001,2005,2009

byRogerS.PressmanFornon-profiteducationaluseonlyMaybereproducedONLYforstudentuseattheuniversitylevelwhenusedinconjunctionwithSoftwareEngineering:APractitioner'sApproach,7/e.Anyotherreproductionoruseisprohibitedwithouttheexpresswrittenpermissionoftheauthor.AllcopyrightinformationMUSTappeariftheseslidesarepostedonawebsiteforstudentuse.1编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005SQA元素标准评审与审核测试相关错误/缺陷收集与分析变更管理培训供应商管理安全管理安全

风险管理2编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005SQA组的角色——I对于项目，准备一个SQA计划计划标识了

准备执行的评估

准备执行的审计与复审

应用于项目的标准

错误报告和跟踪的过程

由SQA组构造的文档给软件项目团队提供的反馈

参与项目软件过程描述的定义SQA组复审项目过程描述是否与企业规定，内部软件标准，外部标准（如ISO-9001）一致

3编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005SQA组的角色——II评审软件工程活动，用于验证这些活动与定义的软件工程过程的兼容性

识别，记录和跟踪与该软件过程的偏差，并验证是否得到改正。审核制定的软件工作产品，以验证其是否符合定义的软件过程中的相应部分。确保软件工作及工作产品中出现的偏差已文档化，并且按照文档化的规程进行了处理记录所有不符合的部分，并报告给高层管理者4编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005SQA目标需求质量设计质量代码质量质量控制有效性.5编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005为什么SQA活动是值得的?改正一个错误的相对成本10010logscale1Req.Designcodetestsystemtestfielduse0.751.001.503.0010.0060.00-100.006编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005基于统计的SQA产品&过程度量...如何增进质量的一个理解

收集所有的缺陷信息

找到缺陷的原因

专向弥补缺陷的过程7编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005StatisticalSQAInformationaboutsoftwareerrorsanddefectsiscollectedandcategorized.Anattemptismadetotraceeacherroranddefecttoitsunderlyingcause(e.g.,non-conformancetospecifications,designerror,violationofstandards,poorcommunicationwiththecustomer).UsingtheParetoprinciple(80percentofthedefectscanbetracedto20percentofallpossiblecauses),isolatethe20percent(thevitalfew).Oncethevitalfewcauseshavebeenidentified,movetocorrecttheproblemsthathavecausedtheerrorsanddefects.8编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005软件Six-Sigma“sixsigma”这个术语来源于6个标准方差——每百万个操作发生3.4个偏差—它意味着非常高的质量标准。SixSigma方法学定义了3个主要步骤:定义度量分析改进控制9编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005软件可靠性一个简单的可靠性的度量是mean-time-between-failure

(MTBF),此处

MTBF

=

MTTF

+

MTTRMTTF（mean-time-to-failure

）与MTTR（mean-time-to-repair）,软件可用性是指在某个时间点上程序能够按照需求执行的概率。

可用性

=

[MTTF/(MTTF

+

MTTR)]

x

100%

10编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005软件安全性Software

safety

isasoftwarequalityassuranceactivitythatfocusesontheidentificationandassessmentofpotentialhazardsthatmayaffectsoftwarenegativelyandcauseanentiresystemtofail.Ifhazardscanbeidentifiedearlyinthesoftwareprocess,softwaredesignfeaturescanbespecifiedthatwilleithereliminateorcontrolpotentialhazards.11编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005软件安全性软件安全是一种软件质量保证活动，它主要用来识别和评估可能对软件产生负面影响并促使整个系统失效的潜在灾难。如果能够在软件过程的早期阶段识别出这些灾难，就可以指定软件设计特性来消除或控制这些潜在的灾难。12编辑pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright©1996,2001,2005ISO9001:2000标准ISO9001:2000是适用于软件工程的质量保证标准。ISO9001:2000描述的质量要求涉及：管理者责任、质