owned163

Y.
Shietal.
(Eds.
):ICCS2007,PartII,LNCS4488,pp.
1115–1122,2007.
Springer-VerlagBerlinHeidelberg2007SoftwareProductLineOrientedFeatureMapYiyuanLi,JianweiYin,DongcaiShi,YingLi,andJinxiangDongCollegeofComputerScienceandTechnology,ZhejiangUniv.
,Hangzhou310027,Chinazjulyy@yahoo.
com.
cn,zjuyjw@zju.
edu.
cn,shidcai@163.
com,cnliying@zju.
edu.
cn,djx@zju.
edu.
cnAbstract.
Thecoreideaofsoftwareproductlineengineeringistodevelopareusableinfrastructurethatsupportsthesoftwaredevelopmentofafamilyofproducts.
Onthebaseofdomainanalysis,featuremodelingidentifiescommonalitiesandvariabilityofsoftwareproductsintermsoffeaturestoprovideanacknowledgedabstracttovariousstakeholders.
Theconceptoffeaturemapisproposedtoperfectfeaturemodel.
Itsupportscustomizedfeaturedependenciesandconstraintexpresses,providesthecapabilitytonavigateandlocatetheresourceentitiesoffeatures.
Ontologyisintroducedastherepresentationbasisforthemeta-modeloffeaturemaps.
Bythemeansofselectingfeaturestoconstructthereusableinfrastructure,thecomponentsoffeatureimplementationarerapidlylocatedandassembledtoproduceafamilyofsoftwareproductsmeetingcertaindependenciesandconstraints.
Keywords:Variability,Featuremap,Resourcenavigation,Ontology.
1IntroductionCurrentlythemanufactureofsoftwareissufferingfromsuchproblemsasindividualcustomizedrequirementsandfrequentchangesofbusinessrequirements.
Asaresult,itseemsthattraditionalsoftwaredevelopmentmode-whichistodevelopsoftwareproductspecificallyforcertainapplication'srequirements-costsmoreandhaslessefficiencyandmaintainability.
Inthissoftwaredevelopmentmode,it'shardtomeettherequirementsofsoftwaredevelopmentinlargescalecustomizationenvironment.
Thepurposeofsoftwareproductionformasscustomizationistoproduceandmaintainafamilyofsoftwareproductswithsimilarfunctions,figureoutboththeircommonalitiesandvariabilityandmanagethesefeatures[1].
Itrepresentsthetrendofsoftwarefactory'sevolution.
Softwareproductlineisaneffectivewaytoimplementsoftwareproductionformasscustomization.
It'sasetofsoftwaresystemswithcommoncontrollablefeatures.
Thecoreideaofsoftwareproductlineengineeringistodevelopareusableinfrastructurethatsupportsthesoftwaredevelopmentofafamilyofproducts[2].
Asoftwareproductlinetypicallyconsistsofaproductlinearchitecture,asetofcomponentsandasetofproducts[3].
Thecharacteristicsofsoftwaredevelopmentapplyingsoftwareproductlineprincipalsaretomaintainthecommonsoftwareassetsandreusethemduringthedevelopmentprocess,suchasdomainmodel,software1116Y.
Lietal.
architecture,processmodel,components,etc.
Eachproductderivesitsarchitecturefromtheproductlinearchitecture,instantiatesandconfiguresasubsetoftheproductlinecomponentsandusuallycontainssomeproduct-specificcode.
Instantiatedproductsconstituteafamilyofsoftwareproductsindomain.
Featuremodelingisthemainstreamofdomainanalysisforthesoftwareproductline.
Itsmainpurposeistoidentifyallcommonalitiesandvariabilityinsoftwareproductline.
Theoutputsoffeaturemodelingareallpotentialproductsofproductline[4].
FORM[5]isafamousdevelopmentmethodbasedonfeature.
Differencebetweendomainproductsandfamilyproductsshowsthevariabilityofsoftwareproductline[2].
Variabilitypointmodel[6,7]modelsthevariabilityofsoftwareproductlinethroughfourways.
Thecomplexdependencyrelationshipsamongvariabilitypointsarepresentedinfirstorderexpression[8].
Fromtheviewpointofsoftwareconfigurationmanagement,thevariabilitymanagementofsoftwareproductlinecanbedividedintoninesubmodulesaccordingtotwodimensions[9].
Byanalyzingthedeficiencyofcurrentfeaturemodelinganditsdescriptionlanguage,thispaperproposesanexpandedfeaturemodelingofsoftwareproductline–featuremap.
Itperfectsfeaturedependencydescriptionandrestrictionexpression,supportsquicknavigationtofeatureresourceartifactsofsoftwareproductlineindistributedcollaborativedevelopmentenvironment.
Itsmeta-modelisalsopresented.
2FeatureMapFeatureisthefirst-orderentityindomain.
Itshowssomecapabilitiesorspecialtiesownedbysystems.
It'stheonlydeterminateabstractinthedomainandcanbeunderstoodsimultaneouslybydomainexperts,usersanddevelopers.
Toacertainextent,featureisakindofexpressiontoontologyknowledgeofapplicationdomain.
2.
1DeficiencyofFeatureModelFeaturemodelingistoidentifythecommonalitiesandvariabilityofallproductsinasoftwareproductlineviaanalysistodomainfeaturesandtheirrelationship.
Domainreferencearchitecturecanbebuiltaccordingtofeaturemodel.
Theconstituentunitsofthearchitecturecanbeboundwithrelatedcomponententities.
However,existingfeaturemodelanditsdescriptiontechniquehavesomedeficiency.
Firstly,eachdomainmayhaveitsownfeaturemutualoperationrelationduetoitsvariety.
Ithasindetermination.
Althoughexistingfeaturemodelssumupandanalyzetheusualfeaturerelation,theycannotwhollydescribealldomainrelatedfeaturedependencyrelation.
Secondly,existingfeaturemodeltrendstobuildfeaturemodelbyaimingatdomainsystems'function.
Thisformsthefunctionalfeatures.
However,itseldomconsidersthenon-functionaldomainfeatureslikeperformance,cost,andthroughputetc.
Alsoitlackseffectivedescriptionandexpressionmeasure.
Thirdly,domainfeatureanalysisrunsthroughallphasesofsoftwaredevelopmentlifecycle.
Itreferstoalotofresourceentitieslikerequirementspecification,designmodelandcomponententitiesetc.
Existingfeaturemodelsonlydiscussproductionofsoftwareproductfromtheviewpointoffeatureselection.
Theyignoretheproblemoffeatureinstantiationincludingtheselectionandlocatingofdomainfeaturerelatedresourceentities.
Fourthly,theremayexistmorethanonecomponententitythatimplementsSoftwareProductLineOrientedFeatureMap1117thefunctionspresentedbyacertainfeatureforchoices.
Existingfeaturemodelsignorethevariabilitybroughtbyfeatureimplementationscheme.
Thusitcanbeseenthatitisnecessarytoexpandexistingfeaturemodelstoperfectthemodelinganddescriptionabilityforfeaturedependencyrelationship,non-functionalfeatureconstraint,featureresourcenavigationandvariabilityofdomain.
2.
2DefinitionofFeatureMapThispaperproposestheconceptoffeaturemap.
Itsupportsfeaturedependencyrelationshipandrestrictionexpressionandprovidesthecapabilityoflocatingandnavigatingresourceentitiestoimplementfeatureselectingaccordingtospecifiedrequirement,locateandassembleresourceentitiesquicklyandgeneratesoftwareproductfamilythatcansatisfydependencyrelationshipandrestrictionconditions.
Afeaturemapcanbedefinedasa5elementsset.
FM=(F,A,C,R,λA,λC,λR),amongthem,-Fisthefeaturesetoffeaturemap;-Aisthefeatureassociationsetoffeaturemap;-Cisthefeatureconstraintexpressionsetoffeaturemap;-Risthefeatureresourceentitysetoffeaturemap;-λAdenotesamappingfromFtothesetP(A),i.
e.
λA:F→P(A).
P(A)representsthesetofallthesubsetsofA.
λAmeetsthefollowingconditions:2aAFFFand'()AfFfaλ∈=,Thismeansthatanarbitraryfeaturecanhavemultipledependencyrelationshipswithotherfeatures.
Meanwhile,eachfeatureassociationinvolvesatleasttwofeatures.
-λCdenotesamappingfromFtothesetP(C),i.
e.
λC:F→P(C).
P(C)representsthesetofallthesubsetsofC.
λCmeetsthefollowingconditions:1cCFFFand'()CfFfcλ∈=,Thatistosay,foranarbitraryfeature,itcanberestrictedbymultipleconstraintexpressions;whileeachfeatureconstraintcanbespecifiedtoeitheracertainfeature,orasetoffeatures.
-λRdenotesamappingfromFtothesetP(R),i.
e.
λR:F→P(R).
P(R)representsthesetofallthesubsetsofR.
λRmeetsthefollowingconditions:RRffFffλλand()RfRλ=∪Thatistosay,eachfeatureownsitsresourceentities.
Thusitcanbeconcludedthattheconceptoffeaturemapconsistsoftwoparts.
Ontheonehand,featuremapexpandsexistingfeaturemodelstoconstructitsinfrastructureandfoundationviaperfectingfeaturedependencyrelationshipdefinitionofexistingfeaturemodelsandaggrandizingfeatureconstraintexpressiontoenhancethefeatureconfigurationrelationship.
Ontheotherhand,featuremapbuildsitssuperstructureviaintroducingtheresourceentitiesoffeaturesandprovidingthecapabilitytorapidlynavigateandlocatethem.
Withthesetwohandscombinedtightly,bythemeansofselectingfeaturestoconstructthereusableinfrastructure,the1118Y.
Lietal.
componententitiesoffeatureimplementationarerapidlylocatedandassembledtoproduceafamilyofsoftwareproductsmeetingcertaindependenciesandconstraints.
2.
3Meta-modelofFeatureMapFeaturestogetherwiththeirdependencyrelationship,constrainexpressionandresourceentitiesareabstractedasbasicelementsofmeta-model.
CorrespondingwiththewebontologylanguageOWL,modelingelementsofmeta-modelcanbedividedintoontologyclasselement,objectpropertyelement,datapropertyelementanddatatypeelement.
Amongthem,ontologyclasselementrepresentsthesemanticprincipal;objectpropertyelementrepresentstheassociationrelationshipamongontologyclasselementsastheformatofobjectpropertyofontologyclasselements,bothitsdomainandrangeareontologyclasselements;datapropertyelementrepresentsthenon-functionalcharacteristicsofontologyclasselement,itsdomainisontologyclasselementwhileitsrangeisdatatypeelement.
Fig.
1.
TheMetaModelofFeatureMapBasedonOntologyThemetamodeloffeaturemapbasedonontologyisdescribedasfigure1,Feature,FeatureBind,Association,ConstraintandResourceetc.
aredefinedasontologyclasses;whilerestrictsObject,hasResource,playedByandhasRoleetc.
aredefinedasontologyobjectpropertiestoestablishtherelationnetworkofsemanticprincipal;name,param,andlocationetc.
aredefinedasdatapropertiestodescribethefeaturepropertiesofsemanticprincipal.
Themeaningsofthemainmeta-modelelementsaredescribedasfollowing:SoftwareProductLineOrientedFeatureMap1119Feature:ontologyexpressionoffeaturedefinitioninfeaturemap,it'scommonorvariablesystemcharacteristicthatcanbeobservedexternally.
Featureontologyinstanceisidentifiedbyauniqueglobalname.
FeatureBind:ontologyclassoffeaturebinding,itassociatesthebindingmodeandbindingtimethroughbindModeandbindTimeobjectpropertiesrespectively.
Mode:bindingmodeoffeature,includingmandatory,optional,or,alternativeandexcludeetc.
modes.
Classifiedfromtheviewpointofifthisbindingmodeisaffectedbythatofotherfeatures,mandatoryandoptionalareunarybindingmodeswhileor,alternativeandexcludeetc.
aremultiplebindingmodes.
However,ifit'sclassifiedfromtheviewpointofthevariabilityoffeatures,onlyfeaturesindicatedbymandatoryarethecommonindispensableswhiletheonesindicatedbyothersareoptionalfeaturesrestedwiththespecificsoftwareproducts.
Time:bindingtimeoffeature,itonlymakessensetothevariablefeaturesthatareindicatedbyoptional,or,alternativeandexcludeetc.
Itsvaluecanbedesign-time,compile-time,implement-time,assemble-time,load-time,instantiate-time,runtimeetc.
Resource:expressionoffeatureresource.
ItmarksthesoftwareproductdevelopmentphaseproducingtheresourceviatheassociationofbelongsToobjectpropertyandPhaseontologyclass.
ItalsoindicatesthetypeofentityobjectquotedbytheresourceviatheassociationoftypeobjectpropertyandResourceTypeontologyclass.
Resourcetypeisdecidedbythephaseofsoftwareproductdevelopment.
Entitiesquotedbytheresourcemaylocateonanyplacesinthedistributednetworkenvironment,andcanbenavigatedbyURIthroughlocationobjectproperty.
Phase:stagesofsoftwareproductdevelopment.
Itincludesrequirement,design,implementation,testandmaintenanceetc.
Althoughsoftwareproductlineengineeringbasedonfeaturemodelingismacroscopicallysimilarwiththetraditionalsoftwareengineeringwhichisorientedtosinglesoftwareproductdevelopmentintheaspectofdefiningthephasesofsoftwaredevelopment,theyaredramaticallydifferentintheaspectofconcreteactualizingapproachanddetailineachphase[10].
ResourceType:itcanberequirementsanalysisdocument,model/flowdesignorcomponentartifactsetc.
Thisdependsonthephaseofsoftwareproductdevelopmentduringwhichthisresourceisproduced.
Constraint:thenon-functionalrestrictionsonfeature.
Constraintexpressionconsistsofasetofparameters,operatorsandvariables.
ConstraintbuildsassociationwithFeatureontologyclassthroughrestrictObjectobjectpropertyandconfirmstherestrictedobject.
Constraintcanbedefinedtoaimatpropertysetofasinglefeature.
Italsocanincludemultiplefeaturesasrestrictedobjectsandbuildfeatureconstraintrelationshipunderthegeneralrestriction.
Association:relationshipsbetweenfeatures.
ItassociatestheAssociationTypeontologyclassthroughthetypeobjectpropertytoconfirmrelationtype.
ItalsoassociatesRoleontologyclassthroughthehasRoleobjectpropertytomakecertaintheobjectsreferredbyassociation.
Itisbuiltbasedonatleasttwoassociatedobjects.
AssociationType:typeofassociation,includingcomposed-of,implemented-by,require,generalization/specializationandactivateetc.
Associationhasorientations,amongwhich,composed-of,generalization/specializationandimplemented-bybelongtostructuralassociation;requireandactivatebelongtoreferenceassociation.
1120Y.
Lietal.
Role:theobjectreferredbyassociation.
ItassociatesFeatureontologyclassthroughplayedByobjectpropertytomakecertaintherealfeaturethatassumestherole.
ItalsoassociatesRoleTypeontologyclassviatypeobjectpropertytoindicatethedeservedroletype.
Assigningofroletypedeterminestheorientationofassociation.
RoleType:typeofrole.
Itsrealrangeisdecidedbythetypeofassociationaccompanyingwiththerole.
Thehierarchyoffeaturemapisbuiltbyrelationshipslikecomposed-of,generalization/specialization,implemented-byetc.
amongfeatures.
Commonfeaturesarerepresentedbysettingbindingmodetomandatorywhilevariablefeaturesareestablishedbymarkingthebindingmodeasoptional,or,alternativeorexcludeetc.
Ontheonehand,dependencyandmutualoperationamongfeaturesareexpressedbyassociationslikeimplemented-by,requireandactivateetc.
Moreover,theorientationsofassociationsaredeterminedbytherolethatfeaturetakeswithinassociation.
Ontheotherhand,constraintexpressionsarebuiltonthepropertiesofasinglefeatureorthepropertiessetoffeaturegroup.
Allkindsofresourceentitiesrelatedtofeaturesineachdevelopmentphasearenavigatedinnetworkenvironmentbylocation.
Throughthisway,structuralassociation,dependencyassociationandconstraintconditionsamongfeaturesarecompletelyestablished.
Meanwhile,byaddinginstancesofAssociationType,RoleTypeandResoureType,meta-modelcandescribethenewassociationsandlocatethenewresourceentities.
Thusexpansibilityisavailable.
Thevariabilityoffeaturemapisrepresentedinseveralaspects.
Firstly,asfarasbindingmodeandbindingtimeareconcerned,theformerdirectlydetermineswhetherthefeatureisselectedornot,whilethelatterdeterminestheoccasionwhentheoptionalfeaturesareinstantiated.
Secondly,therelationsamongfeatureslikerequireandactivateetc.
determineiftheotherfeaturesthathavedependencyassociationormutualoperationassociationwiththepresentfeaturewillbeselectedornot.
Thirdly,constraintexpressiondeterminesthequantificationconstraintonthepropertiessetofasinglefeatureorfeaturegroup,andfurthermore,itwillaffecttheselectionofcomponententitiesforfeatureimplementation.
Fourthly,onthebaseofthenavigationandlocatingofresourceentities,softwareproductsinstantiatedbyselectingresourceentitieswithsamefunctionsbutdifferentimplementationplanwillhavedifferentnon-functionalcharacteristicslikeperformanceandqualityofserviceetc.
3CaseStudyFigure2showsthefeaturemapofmobiletelephonesoftwareproductlineandthemappingtoitsmeta-model.
Mobiletelephonesoftwareproductlineiscomposedofsomefunctionalfeatureslikepasswordprotection,game,telephonedirectoryandbrowseretc.
Amongthem,passwordprotectionandbrowserareoptionalfeatures.
Meanwhile,multiplegamescanbethechoice,buttosomelimitation,suchasasmallmemorycapacity,G3andG4canonlybechosenonearbitrarily.
Inordertobeinoperation,thelengthofpasswordshouldbesetto6,thelengthoflistinthetelephonedirectoryshouldbenomorethan250,andtherequiredmemoryofembeddedbrowsershouldbelessthan2M.
Intheprocessoffeatureanalysis,eachfunctionfeaturehasrelatedrequirementsspecification,designmodelandimplementationcomponent.
Somefunctionalfeatures,forexample,G2,evenhavevariousimplementationschemes.
SoftwareProductLineOrientedFeatureMap1121Functionalfeatureslikepasswordprotection,game,telephonebookandbrowseretcaremodelingasFeatureontology;theselectionoffeatureismandatoryoroptionalismodelingasModeontology;maxlengthofpassword,volumeoftelephonebookandmemoryconsumedbybrowseretc.
aremodelingasConstraintontology;hierarchystructureoffeaturesandthemutuallyexclusiverelationshipbetweenG3andG4etc.
aremodelingasAssociationontology;requirementsdocument,designmodelsandcomponententitiesaremodelingasResourceTypeontology;alllifecyclephasesofsoftwaredevelopmentaremodelingasPhaseontology.
Thewholeinfrastructureoffeaturemapisconstructedbytheassociationsamongontologyviaobjectproperties,whilethesuperstructureoffeaturemapisconstructedbymodelingthereferenceofresourceaslocationpropertytonavigateandlocatetheresourceentities.
Fig.
2.
FeatureMapandItsMeta-modelofMobileTelephoneSoftwareProductLine4ConclusionThecoreideaofsoftwareproductlineengineeringistodevelopareusableinfrastructurethatsupportsthedevelopmentofafamilyofsoftwareproducts.
It'sanefficientwaytoimplementmasscustomizedsoftwareproduction.
Featuremodelingisthemainstreamofdomainanalysisofsoftwareproductline.
Itidentifiescommonalitiesandvariabilityoftheproductsofaproductlineintermsoffeaturestoprovideanacknowledgedabstracttovariousstakeholders.
Uncertaintyofvariablefeaturesdeterminesthevariabilityofsoftwareproductline.
Existingfeaturemodelsandtheirdescriptioncannotentirelysupportthediversityoffeaturedependenciesin1122Y.
Lietal.
differentdomains.
Theydonotsupportmodelinganddescriptionofconstraintexpressionandcannotnavigateandlocatetheresourcesinnetworkenvironment.
Moreover,theirvariabilityanalysisdidnotconsiderthealternativeofcomponententitieswhichimplementthefeatures.
Inthispaper,theconceptoffeaturemapisproposedtoperfectfeaturemodel.
Ontologyisintroducedastherepresentationbasisforthemeta-modeloffeaturemap.
Featuremapsupportscustomizedfeaturedependenciesandconstraintexpressions,providesthecapabilitytonavigateandlocatetheresourceentitiesoffeatures.
Thenbythemeansofselectingfeaturestoconstructthereusableinfrastructure,thecomponentsoffeatureimplementationarerapidlylocatedandassembledtoproduceafamilyofsoftwareproductsmeetingcertaindependenciesandconstraints.
Thefurtherworkistorefinethefeaturemapduringstudiesandpractices,includinghowtodefineanddescribeitsrelatedactioncharactersandstatetransferetc.
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