Model-Driven Evolution of Software Architectures - Software and ...
Model-Driven Evolution of Software Architectures - Software and ...
Model-Driven Evolution of Software Architectures - Software and ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
162 Chapter7. <strong>Model</strong>-<strong>Driven</strong>Migration<br />
accountforapproximately10-20%<strong>of</strong>thesourcecodeforourSMCcomponents.Theapplication<strong>of</strong>ourtransformationrulestothetworepresentativeexamplespresentedinthischapterrequireslessthan10secondsto<br />
completeona1.7GHznotebook. Furthermore,weexpecttheexecution<br />
timetobelinearwithrespecttothenumber<strong>of</strong>requests. Moreimportant<br />
fortheexecutiontimeisthenestingdepth<strong>of</strong>conditionalpaths. Forour<br />
industrialcasewehavenotencounteredrequestswithdeepernestingthan<br />
ourexamplerequests.<br />
Effectiveness Ourmodel-drivenapproachrequiresthatimplicitdesigndecisions<strong>and</strong>designknowledgeisconsolidated<strong>and</strong>madeexplicitforthedefinition<strong>of</strong>metamodels<strong>and</strong>transformationrules.<br />
Assuch,theapplication<br />
<strong>of</strong>ourapproachtothe SMCcomponents<strong>of</strong>ourcasestudyincreasedthe<br />
generalunderst<strong>and</strong>ing<strong>of</strong>concerns<strong>and</strong>theassociatedimplications(<strong>and</strong><br />
difficulties)surroundingthearchitecturemigration<strong>of</strong>SMCsystems.Moreover,theneedforexpertsonboththedomain<strong>and</strong>thetargetparadigmwas<br />
confinedtothedefinition<strong>of</strong>thenormalisation<strong>and</strong>transformationrules.<br />
Theeffectiveness<strong>of</strong>boththeMDAapproach<strong>and</strong>ourmodel-drivenmigrationapproachdependspartiallyontheability<strong>of</strong>modelling,transformation<strong>and</strong>codegenerationtoolstocooperate.<br />
Assuch,st<strong>and</strong>ardsinvolved<br />
withtheMDA,suchasMOF,UML,<strong>and</strong>particularlyXMI,playanimportant<br />
role. Inpractice,theavailability<strong>of</strong>differentversions<strong>of</strong>thesespecificationsmadeitdifficulttosetupanappropriatetoolchain.Forinstance,we<br />
couldnotusethelatestversion<strong>of</strong>ourUMLmodellingtool(i.e.,’Poseidonfor<br />
UML’)becausetheUMLmetamodelituses,wasincompatiblewiththeATL<br />
transformationengine.Althoughwetooktheliberty<strong>of</strong>selectingtoolsthat<br />
wereabletocooperate,westillneededtoimplementsomeadditionaltransformationsusingExtensibleStylesheetLanguageTransformations<br />
1 (XSLT)<br />
toovercomesomeincompatibilitiesbetweenthevarioustools.Inindustry<br />
itwillnotalwaysbepossibletoselectaspecificset<strong>of</strong>toolsforthemigrationgivenpracticalconsiderationssuchaslicensing,support,<strong>and</strong>training<br />
costs.<br />
Apartfromtoolsupport,therequiredhumaninterventionduringthe<br />
normalisationstepalsodeterminestheeffectiveness<strong>of</strong>ourmigrationapproach.Thecomplexity<strong>of</strong>thenormalisationstepdependsonthenumber<strong>of</strong>constraintsthattherestrictedsourcemetamodeladdstothelegacy<br />
sourcemetamodel(ifpresent).Here,atrade-<strong>of</strong>fapplies:fewerconstraints<br />
makethetransformation,whichistypicallyautomated,morecomplexbecausemorespecificationalternativeshavetobecovered.<br />
Forinstance,if<br />
wewouldallowActionscorrespondingtomanufacturingactivitiestooccur<br />
asActionsonTransitions,searchingforpredecessorswouldbecomemuch<br />
1 http://www.w3.org/TR/xslt(June2007)
Change language