第十三章軟件質(zhì)量保證SlideSettoaccompany

SoftwareEngineering:APractitioner’sApproach,7/e

byRogerS.PressmanSlidescopyright?1996,2001,2005,2009

byRogerS.PressmanFornon-profiteducationaluseonlyMaybereproducedONLYforstudentuseattheuniversitylevelwhenusedinconjunctionwithSoftwareEngineering:APractitioner'sApproach,7/e.Anyotherreproductionoruseisprohibitedwithouttheexpresswrittenpermissionoftheauthor.AllcopyrightinformationMUSTappeariftheseslidesarepostedonawebsiteforstudentuse.1編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005SQA元素標準評審與審核測試相關(guān)錯誤/缺陷收集與分析變更管理培訓供應(yīng)商管理安全管理安全

風險管理2編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005SQA組的角色——I對于項目，準備一個SQA計劃計劃標識了

準備執(zhí)行的評估

準備執(zhí)行的審計與復(fù)審

應(yīng)用于項目的標準

錯誤報告和跟蹤的過程

由SQA組構(gòu)造的文檔給軟件項目團隊提供的反饋

參與項目軟件過程描述的定義SQA組復(fù)審項目過程描述是否與企業(yè)規(guī)定，內(nèi)部軟件標準，外部標準（如ISO-9001）一致

3編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005SQA組的角色——II評審軟件工程活動，用于驗證這些活動與定義的軟件工程過程的兼容性

識別，記錄和跟蹤與該軟件過程的偏差，并驗證是否得到改正。審核制定的軟件工作產(chǎn)品，以驗證其是否符合定義的軟件過程中的相應(yīng)部分。確保軟件工作及工作產(chǎn)品中出現(xiàn)的偏差已文檔化，并且按照文檔化的規(guī)程進行了處理記錄所有不符合的部分，并報告給高層管理者4編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005SQA目標需求質(zhì)量設(shè)計質(zhì)量代碼質(zhì)量質(zhì)量控制有效性.5編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005為什么SQA活動是值得的?改正一個錯誤的相對成本10010logscale1Req.Designcodetestsystemtestfielduse0.751.001.503.0010.0060.00-100.006編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005基于統(tǒng)計的SQA產(chǎn)品&過程度量...如何增進質(zhì)量的一個理解

收集所有的缺陷信息

找到缺陷的原因

專向彌補缺陷的過程7編輯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編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005軟件Six-Sigma“sixsigma”這個術(shù)語來源于6個標準方差——每百萬個操作發(fā)生3.4個偏差—它意味著非常高的質(zhì)量標準。SixSigma方法學定義了3個主要步驟:定義度量分析改進控制9編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005軟件可靠性一個簡單的可靠性的度量是mean-time-between-failure

(MTBF),此處

MTBF

=

MTTF

+

MTTRMTTF（mean-time-to-failure

）與MTTR（mean-time-to-repair）,軟件可用性是指在某個時間點上程序能夠按照需求執(zhí)行的概率。

可用性

=

[MTTF/(MTTF

+

MTTR)]

x

100%

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

safety

isasoftwarequalityassuranceactivitythatfocusesontheidentificationandassessmentofpotentialhazardsthatmayaffectsoftwarenegativelyandcauseanentiresystemtofail.Ifhazardscanbeidentifiedearlyinthesoftwareprocess,softwaredesignfeaturescanbespecifiedthatwilleithereliminateorcontrolpotentialhazards.11編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005軟件安全性軟件安全是一種軟件質(zhì)量保證活動，它主要用來識別和評估可能對軟件產(chǎn)生負面影響并促使整個系統(tǒng)失效的潛在災(zāi)難。如果能夠在軟件過程的早期階段識別出這些災(zāi)難，就可以指定軟件設(shè)計特性來消除或控制這些潛在的災(zāi)難。12編輯pptSoftwareEngineering:APractitioner’sApproach,6/eandareprovidedwithpermissionbyR.S.Pressman&Associates,Inc.,copyright?1996,2001,2005ISO9001:2000標準ISO9001:2000是適用于軟件工程的質(zhì)量保證標準。ISO9001:2000描述的質(zhì)量要求涉及：管理者責任、質(zhì)