软件工程课后习题答案

1软件工程课后习题答案Chapter11.1)ThedefinitionforsoftwarepresentedinSection1.2appliestotheWebsites.Thereare,however,subtledifferencesbetweenaWebsiteandconventionalsoftware.AmongthemostimportantarethatthecontentthataWebsitepresentsisconsideredtobepartoftheWebApplicationwhilethatdataprocessedbyconventionalsoftwareisoftenconsideredtobeseparatefromtheprocessingfunctionsdelivered.1.4)Whowouldhavethoughtthatsoftwarewouldleadto:(1)achangeinthedatinghabitsofmanyyoungpeople(Internetdating);(2)thewaypeoplecommunicate(cellphones);(3)methodsofwarfare(cyberweapons);(4)thediagnosisofdiseases(MRIsandrelatedcomputer-baseddiagnosticdevices),and(5)themannerinwhichpeopleacquireandenjoymedia(music,DVDs,etc.).1.6)TheLawofConservationofFamiliarity:Asthesystemevolvestheusersengineers,developersallthoseassociatedmusthavethecompleteknowledgeofthecontentandbehaviortoachievesatisfactoryresults.Increaseingrowthmaydiminishthatknowledge(mastery);hencetheaverageincreaseingrowthremainsinvariantasthesystemevolves.1.7)Manymodernapplicationschangefrequentlybeforetheyarepresentedtotheenduserandthenafterthefirstversionshavebeenused.Afewwaystobuildsoftwaretostopdeteriorationduetochangewouldbe:Makesurethatsoftwareisdesignedsothatchangesinonepartofaprogramdonotcreateside-effectsinanotherpartoftheprogram.Makesurethatsoftwareisdesignedsothatitdoesnotdependonexternaldevicesorsystemsthatarelikelytochangewithtime.Makesuretestcasesandresultsarearchivedandavailablesothatthesoftwarecanberetestedwhenchangesaremade.Makesureyouspendtimeunderstandingwhatthecustomerwants.1.8)Thetwobroadestcategoriesencompassrisksassociatedwitheconomiclossandriskstothewellbeingofpeople.Itmightbeagoodideatoselectfiverisks(culledfromthesourcesnoted)andpresentthemtotheclass.Lookforhumorousaswellasseriousrisks.1.9)Thesameapproachtosoftwareengineeringcanbeappliedforeachofthesixcategories,butitmustbeadaptedtoaccommodatethespecialrequirementsofeachcategory.1.10)Thereareliterallydozensofreallifecircumstancestochoosefrom.Forexample,softwareerrorsthathavecausedmajortelephonenetworkstofail,failuresinavionicsthathavecontributedtoplanecrashes,computerviruses(e.g.,Michelangelo)thathavecausedsignificanteconomiclossesandattacksonmajore-commercesites.1.11)TheLawofDecliningQuality:Thequalityofsystemswilldeclineunlesstheyaremaintainedbyvariousprocedurestoadapttotheenvironmentalchanges.Thisconceptissimilartothe“deterioration”discussedinProblem1-5.1.12)TheLawofConservationofOrganizationalStability:Theaverageeffectiveglobalactivityrateisinvariantoverthelifetimeofaproduct.Chapter22.1)Pattern:CommunicationIntent:Toestablishacollaborativerelationshipwiththecustomerinanefforttodefineprojectscope,businessrequirementsandotherprojectconstraints.”Type:StagepatternInitialcontext:(1)Appropriatestakeholdershavebeenidentifiedandarewillingtoparticipateincommunication(2)StakeholdersagreethataproblemexistsandthatsoftwaremayprovideasolutionProblem:Requirementsmustbeelicitedfromstakeholdersandorganizedinawaythatcanbeusedbysoftwareengineers.Allstakeholdersmustcollaboratetodefinerequirementsandtoidentifythoseareaswhererequirementsareuncertain.Solution:Eachstakeholdermustdevelopadescriptionofthefunctions,features,informationandbehaviorthatareexhibitedbythesoftware.Toaccomplishthis,astructured,facilitatedmeetingisconducted.Formoredetails,seeSections7.3,7.4and7.5.ResultingContext:Whenthispatternhasbeensuccessfullycompleted,basicinformationrequiredforthedevelopmentofananalysismodelhasbeenacquiredanddocumentedinsomemanner.Use-cases(userscenarios)havebeendeveloped,alongwithbasicdescriptionsofsystemfunctionandbehaviorandthedataobjectsthataretobemanipulatedand/orproduced/RelatedPatterns:Conductedameeting;requirementgathering;developinguse-cases;buildingamini-spec;negotiatingrequirements,prioritization.KnownUses/Examples:Communicationismandatoryatthebeginningofeverysoftwareproject;isrecommendedthroughoutthesoftwareproject;andismandatoryoncethedeploymentactivityisunderway.22.2)Processassessmentexaminesthesoftwareprocessusedbyanorganizationtodeterminewhetheritiseffectiveinachievingsoftwareengineeringgoals.Theassessmentcharacterizesthecurrentpracticewithinanorganizationalunitintermsofthecapabilityoftheselectedprocesses.TheSPICE(ISO/IEC15504)standarddefinesasetofrequirementsforsoftwareprocessassessment.Toaccomplishtheassessment,SPICEspecifiesa“referencemodel”thatexaminesthepurposeandmeasurableobjectivesoftheprocess(the“processdimension”)andthesetofprocessattributesthatshouldbepresent(the“capabilitydimension”).2.4)TaskSetforCommunicationActivity:Atasksetwoulddefinetheactualworktobedonetoaccomplishtheobjectivesofasoftwareengineeringaction.Forthecommunicationactivitytheseare:1.Makealistofstakeholdersfortheproject2.Inviteallthestakeholderstoaninformalmeeting3.Askthemtomakealistoffeaturesandfunctions4.Discussrequirementsandbuildafinallist5.PrioritizerequirementsandnotetheareasthatstakeholdersareuncertainofThesetasksmaybeexpandedforacomplexsoftwareproject,theymaythenconsiderthefollowing:Toconductaseriesofspecificationmeetings,buildaprelimin