软件测试与质量保证 Testing (6)学习课件

Topic:SoftwareTestingTechniques(6)INSTRUCTOR:SHULIUHITSCHOOLOFSOFTWARE2017Allrightsreserved1哈工大软件学院刘曙SoftwareTestingTechniquesNon-Execution-BasedTestingWalkthroughInspectionPeerReviews/BuddyChecksExecution-BasedTestingBlack-Box,White-Box,andGray-BoxTestingBasisPathTestingBottom-Up,Top-Down,andSandwichTestingEquivalencePartitioningandBoundaryValueTestingPositiveandNegativeTestingRangeTesting,RegressionTesting,andRandomTestingSoftwareTestingTechniques2哈工大软件学院刘曙SoftwareTestingTechniquesSoftwareTestingTechniquesWhydowetest?Towmainreasons:●

Tomakeajudgmentaboutqualityoracceptability

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Todiscoverproblems3哈工大软件学院刘曙SoftwareTestingTechniquesDuringtherequirementsphase,therequirementsmustbechecked;Duringthespecificationphase,thespecificationsmustbechecked;

Andthesoftwareproductionmanagementplanmustundergosimilarscrutiny(详细审查).Thedesignphaserequirescarefulcheckingateverystage.Duringthecodingphase,eachmodulecertainlymustbetested,andtheproductasawholeneedstestingattheintegrationphase.Afterpassingtheacceptancetest,theproductisinstalledandthemaintenancephasebegins.

…SoftwareTestingTechniquesWhendowetest?4哈工大软件学院刘曙SoftwareTestingTechniquesTestingisanintegralcomponentofthesoftwareprocessacriticalelementofsoftwarequalityassuranceanactivitythatmustbecarriedoutthroughoutthesoftwaredevelopmentlifecycleTwoTypesofTesting:Non-execution-basedtesting(e.g.,review)Execution-basedtesting(e.g.,runtestsagainsttestcases)SoftwareTestingTechniques5哈工大软件学院刘曙Why?Non-Execution-BasedTestingSoftwareTestingTechniquesLimitationswithExecution-BasedTesting:Bythetimetestingoccurs,itistoolatetobuildqualityintotheproduct.Testsareonlyasgoodasthetestcases,notalldefectsarediscoveredduringtesting.Inrealityitisimpossibletotestallsoftware,andexhaustivetestingcodeisimpractical.Isitpossibletoexecuteawrittenspecificationdocument?Theonlyalternativesaretoreviewitascarefullyaspossible.

6哈工大软件学院刘曙CostofQualitySoftwareTestingTechniquesTherequirementstageisoftenwheremorethan50%ofthedefectsareactuallyintroduced.7哈工大软件学院刘曙SoftwareTestingTechniquesTechniqueReview(Verification)AmIbuildingtheproductright?8哈工大软件学院刘曙ThespectrumofREVIEWrangesfromveryinformalpeerreviewstoextremelyformalandstructuredinspections.InspectionsWalkthroughsPeerReviewsorBuddyChecksSoftwareTestingTechniquesTechniqueReview(Verification)9哈工大软件学院刘曙Thecomplexityofareviewisusuallycorrelatedtothecomplexityoftheproject.Asthecomplexityofaprojectincreases,theneedformoreformalreviewsincreases.

Thecentral“event”inreviewis

“meeting”(“开会”)SoftwareTestingTechniquesTechniqueReview(Verification)10哈工大软件学院刘曙Inspections

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(1)Inspectionsaregenerallyconsideredthemostformaltypeofreview.Itisaformallydefinedprocessforverificationofthesoftwareproductthroughoutitsdevelopment.Oneofthemajordecisionswithinaninspectioniswhetherasoftwaredeliverableiseligibletoproceedtothenextdevelopmentphase.SoftwareTestingTechniques11哈工大软件学院刘曙Inspections

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(2)Theinspectionshouldbeconductedbyateamof3-6people.

Forexample,inthecaseofadesigninspection,theteamwillconsistof

Moderator:isbothmanagerandleaderoftheinspectionteamDesigner:representativefromcurrentphaseImplementer:representativefromnextphaseRequirementanalyst:representationfrompreviousphaseTester:anyoneresponsibleforsettinguptestcases(Ofcause,preferablethatthetestershouldbeamemberoftheSQAgroup.)SoftwareTestingTechniques12哈工大软件学院刘曙Inspections

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(3)SoftwareTestingTechniquesInspectionDocumenttobeinspectedRelatedsourcedocumentsGeneraland“tailored”checklistInputOutputInspectionsummaryorreportDataonerrortypes13哈工大软件学院刘曙Inspections

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(4)TherearefiveformalstepsforInspection 1. Overview 2. Preparation 3. Inspection 4. Rework 5. Follow-upSoftwareTestingTechniques14哈工大软件学院刘曙Inspections

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(5)Overview(概述) First,anoverviewofthedocumenttobeinspected(specification,design,code,orplan)isgivenbyoneoftheindividualsresponsibleforproducingthatdocument.Attheendoftheoverviewsession,thedocumentisdistributedtotheparticipants.SoftwareTestingTechniquesOverviewPreparationInspectionReworkFollowUp15哈工大软件学院刘曙Inspections

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(6)Preparation（准备）Inthesecondstep,theparticipantstrytounderstandthedocumentindetail.Checklists/Listsoffaulttypesfoundinrecentinspections,withthefaulttypesrankedbyfrequency,areexcellentaids.Thesechecklistshelpteammembersconcentrateontheareaswherethemostfaultshaveoccurred.SoftwareTestingTechniquesOverviewPreparationInspectionReworkFollowUp16哈工大软件学院刘曙Inspections

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(7)Inspection（检查）Oneparticipantwalksthroughthedocumentwiththeinspectionteam,ensuringthateveryitemiscoveredandthateverybranchistakenatleastonce.Aswithwalkthrough,thepurposeistofindanddocumentthefaults,nottocorrectthem.Thepresenterinaninspectionmeetingisideallynottheproducerorauthorofthedocumentbeinginspected.SoftwareTestingTechniquesOverviewPreparationInspectionReworkFollowUp17哈工大软件学院刘曙Inspections

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(8)Rework（返工）Withinonedaytheleaderoftheinspectionteam(themoderator)mustproduceawrittenreportoftheinspectiontoensuremeticulousfollow-through.Inthisstep,theindividualresponsibleforthatdocumentresolvesallfaultsandproblemsnotedinthewrittenreport.SoftwareTestingTechniquesOverviewPreparationInspectionReworkFollowUp18哈工大软件学院刘曙Inspections

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(9)Follow-upThemoderatormustensurethateverysingleissueraisedhasbeenrecoveredsatisfactorily,byeitherfixingthedocumentorclarifyingitemsincorrectlyflaggedasfaults.Allfixesmustbecheckedtoensurethatnonewfaultshavebeenintroduced.SoftwareTestingTechniquesOverviewPreparationInspectionReworkFollowUp19哈工大软件学院刘曙Inspections(检查)(9)Aessentialcomponentofaninspectionisthechecklist

ofpotentialfaults.Animportantcomponentoftheinspectionistherecordoffaultstatistics.Thedataindicatethatinspectionsareapowerfulandcost-effectivetoolforfaultdetection.SoftwareTestingTechniques20哈工大软件学院刘曙Walkthrough(1)Walkthroughscanbeveryinformalorrelativelyformal(likestructuredwalkthrough),buttheyarelessformalthaninspections.A‘informalwalkthrough’canbeanveryinformalmeetingforevaluationorinformationalpurpose.Littleornopreparationisusuallyrequired.Walkthroughcanbeusedtoreviewmanysystemsdevelopmentdeliverables,includinglogicalandphysicaldesignspecifications,testplans,testcasesaswellascode.SoftwareTestingTechniques21哈工大软件学院刘曙Walkthrough

(2)Thewalkthroughshouldbeconductedbyateamof2-7people.

Forexample,arequirementspecificationwalkthroughteamshouldinclude:Atleastonerepresentativefromtheteamresponsiblefordrawingupthespecification–Requirementanalyst

Themanagerresponsibleforthespecification.AclientrepresentativeArepresentativeoftheteamthatwillperformthenextphaseofthedevelopment--DesignerArepresentativeofthesoftwarequalityassurancegroup--QASoftwareTestingTechniques22哈工大软件学院刘曙Walkthrough(3)Themembersofthewalkthroughteam,asfaraspossible,shouldbeexperiencedseniortechnicalstaffmembersbecausetheytendtofindtheimportantfaults.ThewalkthroughshouldbechairedbytheSQArepresentativebecausetheSQArepresentativehasthemosttoloseifthewalkthroughisperformedpoorlyandfaultsconsequentlyslipthrough.Nowalkthroughshouldlastlongerthan2hours.SoftwareTestingTechniques23哈工大软件学院刘曙Walkthrough

(4)SoftwareTestingTechniquesWalkthroughElementunderexaminationObjectiveforthewalkthroughApplicablestandardsInputReportOutput24哈工大软件学院刘曙Walkthrough(5)TherearetwostepsforwalkthroughPreparationWalkthroughThematerialforthewalkthroughmustbedistributedtotheparticipantswellinadvancetoallowforcarefulpreparation.Eachreviewershouldstudythematerialanddeveloptwolists:AlistofitemsthereviewerdoesnotunderstandAlistofitemsthereviewerbelievesareincorrectSoftwareTestingTechniques25哈工大软件学院刘曙Walkthrough(6)Therearetwowaysofconductingawalkthrough:Participant-drivenDocument-drivenParticipant-drivenParticipantspresenttheirlistsofunclearitemsanditemstheythinkareincorrect.Therepresentativeofthespecificationsteammustrespondtoeachquery,clarifyingwhatisuncleartothereviewerandeitheragreeingthatindeedthereisafaultorexplainingwhythereviewerismistaken.SoftwareTestingTechniques26哈工大软件学院刘曙Walkthrough(7)Document-drivenThepersonresponsibleforthedocumentwalkstheparticipantsthroughthatdocument,withthereviewersinterruptingeitherwiththeirpreparedcommentsorcommentstriggeredbythepresentation.Document-drivengenerallyleadstothedetectionofmorefaultsbecausethemajorityoffaultsatadocument-drivenwalkthrougharespontaneouslydetectedbythepresenter.SoftwareTestingTechniques27哈工大软件学院刘曙Walkthrough(8)Advantage:Advancedpreparationofthereviewersisnot necessarilyrequired.Itispossibletobedonefrequently.Structuredwalkthroughsareaveryeffectivemethodofdetectingerrorsincode.Disadvantage:Itmayleadtodisorganizedanduncontrolledreviews.Itmayalsobestressfulifthedeveloperis conductingthewalkthrough.SoftwareTestingTechniques28哈工大软件学院刘曙GuidelinesforConductingaCodeWalkthrough(Example)1.Havethereviewmeetingchairedbytheprojectmanagerorchiefprogrammer,whoisalsoresponsibleforschedulingthemeeting,reservingaroom,settingtheagenda,invitingparticipants,andsoon.2.Theprogrammerpresentshisorherworktothereviewers.Discussionshouldbegeneralduringthepresentation.3.Followingthegeneraldiscussion,theprogrammerwalksthroughthecodeindetail,focusingonthelogicofthecoderatherthanonspecifictestcases.4.Reviewersasktowalkthroughspecifictestcases.5.Thechairresolvesdisagreementsifthereviewteamcannotreachagreementamongthemselvesandassignsduties,usuallytotheprogrammer,formakingspecificchanges.6.Asecondwalkthroughisthenscheduledifneeded.SoftwareTestingTechniques29哈工大软件学院刘曙ComparisonofInspectionandWalkthroughAwalkthroughisatwo-stepprocessandaninspectionisafive-stepprocess.Theinspectionprocesstakesmuchlongerthanawalkthrough.Theinspectionteamusesachecklistofqueriestoaiditinfindingthefaults.Itgoesdeeperthanwalkthrough.Walkthroughscancovermorematerialthaninspections.Theyprovideanopportunityforlargernumbersofpeopletobecomefamiliarwiththematerial.Inspectiontypicallydealwithrelativelylowvolumesofmaterial.Occasionally,walkthroughsareusedforpurposesofcommunicationratherthanfordiscoveringdefects.SoftwareTestingTechniques30哈工大软件学院刘曙PeerRevieworBuddyChecksSometimesitisinappropriateorimpossibletogetmaterialinspectedorformallyreviewed.Anyformofhumantesting,evenundisciplinedtesting,isbetterthannone.Just