EXECUTABLE MODELS AND MODEL TRANSFORMATIONS: A FRAMEWORK FOR RESEARCH

Transcription

1 EXECUTABLE MODELS AND MODEL TRANSFORMATIONS: A FRAMEWORK FOR RESEARCH Paulus Paskevcus, Marus Bndokas, Adas Kasperavcus, Robertas Daasevcus Kaunas Unversty of Technology, Software Engneerng Departent, Studentu 50, Kaunas, Lthuana, paulus.paskevcus@gal.co, a.kasperavcus@gal.co, robertas.daasevcus@ktu.lt Kaunas Unversty of Technology, Departent of Inforaton Systes, Studentu 50, Kaunas, Lthuana, arus.bndokas@gal.co Abstract. The paper analyses the an concepts of software syste odellng and eta-odellng, dscusses dfferent vews to odels and the odel valdaton proble, presents defntons and a foral descrpton of a odel and odel transforaton process, provdes a foral descrpton of feature odel predcates, and forulates requreents for executable feature odel specfcatons. Models are descrbed as executable specfcatons that can be used for odel valdaton aganst ts eta-odel, odel queryng for ts structural nforaton and propertes, odel coparson and transforaton. Capabltes of Functonal Java and Prolog for specfcaton of executable odel specfcatons are dscussed. Exaple of executable feature odel n Prolog s presented. Keywords: executable odel, eta-odel, feature odel, odel transforaton. Introducton Model-drven software engneerng (MDSE) [] s centred on odels as frst-class doan enttes. Whle n tradtonal software engneerng odels are used for capture and specfcaton of requreents as well as for councaton and sharng of deas between software developers, n MDSE odels are prary artefacts of product developent, whch capture key features of a developed syste, serve as a source of nforaton about the syste and ts propertes, and are used to valdate the pleentatons of the developed syste. Executable odels are portant as hgh-level workng prototypes of the developed syste or parts thereof, the correctness and consstency of whch could be proven forally. Such executable odels are actve agents of software developent process, whch are used to transfor between dfferent levels of abstracton, to refne and generate syste code and other developent artefacts as well as to perfor syste valdaton and verfcaton. These actvtes deand forally specfed, proven and coputer-processable odels wth syntax and seantcs precsely defned usng a stack of ncreasngly abstract eta-odels. Motvaton for the developent of executable odel specfcatons s to speed up the product odellng and developent te, and to ncrease the qualty and antanablty of developed systes. The expected benefts are valdaton of feature odels and analyss of product feature characterstcs at a early stage of product lne developent. However, executable odels ay requre sgnfcant efforts and nvestent to develop, whch could pay-off only f the end-products are produced on a ass scale thus allowng to acheve substantal reuse. Currently, such a can be acheved usng product lne engneerng [] ethodology and assocated technologes (feature odellng [3], generatve prograng [4], eta-prograng [5], etc.) as a developent platfor. The a of ths paper s to analyse the an concepts of odellng and eta-odellng, to defne odels and odel transforatons forally, and to forulate requreents for executable odel specfcatons (we focus on executable feature odels). The structure of the paper s as follows. Secton dscusses defntons of a odel, ts representaton and valdaton proble. Secton 3 dscusses odel transforatons and presents a odel transforaton fraework. Secton 4 analyses operatons (predcates, transforatons) defned on feature odels. Secton 5 consders an pleentaton of executable feature odels usng Functonal Java and Prolog language. Secton 6 forulates further research as and drectons. Fnally, Secton 7 presents conclusons. Concept of a odel. Overvew of defntons of a odel The concept of odel s one of the ost dscussed concepts n software engneerng wth any defntons gven. We present an overvew of soe of these defntons categorzed nto several vews on odels: ) Descrptonal vew: a odel s a descrpton of a (part of) systes wrtten n a well-defned language" [6]; or nforaton on soethng (content, eanng) created by soeone (sender) for soebody (recever) for soe purpose [7]. In fact, any software artefact such as a progra or a requreent docuent can be understood as a odel wrtten n a specfc language wth ts own syntax and seantcs.

2 ) Foral vew: a odel s a set of truth-valued stateents about soe syste under study [8]. Accordng to ths vew, odels can be created fro a foral lst of syste s propertes and characterstcs, descrbed usng a foral logc notaton and used to valdate the developed syste. Matheatcally, such odel can be descrbed as a rng wth a set of doan enttes as data and a set of operatons defned over the. 3) Autoaton vew: a odel s a graph where the nodes represent the states of a progra and the lnks represent the transtons between these states [9]. A graph as a atheatcal structure s a very flexble representaton, and a wde range of software and knowledge engneerng odels, ncludng UML odels and ontologes, can be expressed usng partcular knds of graphs, such as d-graphs, hyper-graphs or eta-graphs. 4) Ontologcal vew: a odel s an ontology of doan knowledge relevant to the developent of a syste. Such ontology provdes a vocabulary, whch can be used to odel a syste, ncludng the type of obects and/or concepts that exst, and ther propertes and relatons [0]. Stateents on odels can be forulated n the for of the subect-predcate-obect expressons. Such expressons ake a bass of RDF data odel used n ontology defntons. 5) Oracle vew: a odel s a splfcaton of a syste bult wth an ntended goal n nd. The odel should be able to answer questons n place of the actual syste []. Therefore, a odel can be used as a knowledge base to provde the developer wth nforaton about the syste and, based on the facts and ther relatons stored n ths knowledge base, to be able to reason and answer questons about syste propertes, whch are not found n syste requreents, but can be deduced fro other propertes of the syste.. Glass-box vew on a odel Based on the odel defntons, we present the followng vew of a odel, whch we have adopted for our research. Internally, a odel s a collecton of known facts about a odelled syste and ther relatons, whch s descrbed usng a ult-graph (.e., a graph whch can have ultple edges between the vertces). Let odel M be a ult-graph M ( E, R, P) { p p = ( E, E r) } E, E E, R =, where E s a set of eleents, R s a set of relatons, and P =,, E r s a set of appngs between subsets of E. Externally, a odel s an executable specfcaton that provdes a nuber of functonal servces to ts users. As such an executable n k odel can be descrbed as a rng defned over set of functons: M E = ( M, F,, F ), where F are sets of functons wth arty k. Soe of the functons of the executable odel are defned below. Let F be the exstence predcates for each eber of M. Functons return TRUE, f an eleent or relaton s defned n a odel, otherwse FALSE. Let eleent exstence predcate be f E : E B, such that e B, where e E, and B s a Boolean doan. Let relaton exstence predcate be f R : R B, such that r B, where R F L f P r. Let appng exstence predcate be : P B Let : ( E, E) B, such that p B, where p P. be the path predcates, whch return TRUE f there s a path between two eleents n a odel. Path functons can be used to check whether a odel s coplete and consstent. We consder these path predcates: F drect relaton between two eleents n a odel, F ndrect relaton. 3 Let F be the pattern (sub-graph) predcates. Let M be a sub-odel of M. Then the pattern predcates 3, f E E, R R, P P. The path predcates can be used to defne pre-condtons and post-condton for odel transforatons. defne the exstence of M n M: f ( E, R P ) TRUE.3 Valdty of odels A eta-odel can be consdered as a theory (axoatc syste) that can be used to deduce new stateents about a syste fro the stateents already present n soe set of odels of the syste. Gven the eta-odel representaton of a odel, we can deterne, usng the theory, whether the odel s representaton s consstent wth the eta-odel. Therefore, the eta-odel of a odel descrbes the structural and functonal requreents that a odel ust follow to be vald. There s a great varety of odels and eta-odels n software engneerng. However, all eta-odels can be reduced to a set of doan enttes (eleents) that descrbe the statc state of doan systes (odels) and a set of relatons between these enttes that descrbe the seantcs of doan. The relatonshp between odel and ts eta-odel s as follows (see Fgure ). Each eleent of a odel ust be defned n a eta-odel,.e., each eleent ust have a correspondng etaeleent, the nstance thereof t s. Relatons between odel eleents also ust be defned as eta-eleents at the eta-odel level. To defne the relatonshps between eta-eleents, a eta-odel ay eploy ts own eta-relatons as a knd of the eta-odellng language abstracton, whch ay be unrelated to odel relatons.

3 Fgure. Generc eta-odel of odels and odel/eta-odel relatonshp We forulate the followng rules for odel conforance to ts eta-odel as follows. Model M confors to ts eta-odel e E e = nstanceof e r R, r = nstanceof e, e E. M, f, ( ); and ( ) Precsely defned eta-odels are a prerequste for specfyng odel transforatons []. The valdty of a eta-odel (.e., ts ablty to defne correct, coplete, coherent and consstent doan syste odels) can be checked usng a set of postve and negatve test odels [3]. Here, a postve doan odel s understood as a odel that descrbes a vald doan syste, and a negatve doan odel s a odel that descrbes an nvald doan syste. Let be a set of postve odel nstances and be a set of negatve p odel nstances. Then a eta-odel M s vald, f p, p confors to M ; and n, n does not confor to M. 3 Model transforatons 3. Defnton of concepts n the odel transforaton doan The theoretcal foundatons of odel transforaton are rewrte systes and se-thue systes fro theoretcal coputer scence [4]. The practcal foundatons of odel transforaton technques have been ntroduced by copler generators. Copler generators translate graar of progras wrtten n a graar descrpton language such as BNF nto progras wrtten n a hgher prograng language (such as C++) to parse progras descrbed by BNF. If odels can be specfed usng textual specfcaton language and the graar of ths language can be expressed usng BNF, then every odel transforaton proble can be reduced to progra transforaton, where progras are hgh-level odel specfcatons. There s a great varety of defnton what a odel transforaton s. Tratt [5] defnes odel transforaton very wdely as "a progra that utates one odel nto another". Obect Manageent Group (OMG) defnes odel transforaton n the context of odel-drven archtecture (MDA) as "the process of convertng a odel nto another odel of the sae syste" [6]. Kleppe et al. [6] defne odel transforaton as the "autoatc generaton of a target odel fro a source odel, accordng to a transforaton descrpton". Mens et al. [] extend ths defnton by allowng several odels as nput or output and defne odel transforaton as "autoatc generaton of one or ultple target odels fro one or ultple source odels, accordng to a transforaton descrpton". Accordng to Kurtev [7], there are three types of odel transforatons: ) Refactorng transforatons reorganze a odel based on soe precsely defned crtera. The output refactored odel s a slghtly versoned odel. ) Model-to-odel transforatons convert one odel to another odel. 3) Model-tocode transforatons convert odels nto progra text. 3. Model transforaton fraework We ntroduce the followng types of odel transforaton:. Model eta-odel (odel lftng): M M, ( E, R, P) ( etaeleentof ( E) etaeleentof ( R), R, P ).. Model odel nstance (odel nstantaton): M k, where k = nstanceof ( M ). 3. Model odel (exogenous odel transforaton): M M, when M M. 4. Model odel (endogenous odel transforaton): M M, when M = M. n

4 5. Model sub-odel (endogenous odel specalzaton): M M, M M.,. a. Reoval of eleent(s): ( M E ) M E, E E, M E M b. Reoval of relaton(s): ( M, R ) M R, R R, M R M. c. Reoval of sub-odel(s): ( M M ) M, M M, M M,. 6. Model super-odel (endogenous odel generalzaton): M M, M M.,. a. Addton of eleent(s): ( M E ) M E, E E =, M E M b. Addton of relaton(s): ( M R ) M R, R R =, M R M c. Addton of sub-odel(s): ( M M ) M, M M,.,. The prerequstes for these odel transforatons are: ) a eta-odel of a source odel, ) a etaodel of a target odel, 3) a eta-odel of a source-target transforaton odel. Accordng to the eta-odel herarchy ntroduced by Kraus [8], these eta-odels ust confor to the sae eta-eta-odel. 4 Executable feature odels As an exaple of the applcaton of concepts ntroduced so far, we, frst, descrbe reasonng on a partcular knd of odels, called feature odels [3], whch are wdely used n product lne engneerng for odellng product features. Further, we forulate the requreents for executable feature odels and dscuss ther pleentaton alternatve usng Functonal Java and Prolog logc prograng language. 4. Reasonng on feature odels and ther transforatons The followng predcates can be defned over feature odels: Exstence of feature. Let F be a feature odel, f be a feature, then exsts s a feature exstence predcate: exsts( F, f ) f F. Drect dependency of a feature. Let F be a feature odel, f be a parent feature, f s a chld feature, chld( F, f, f f f, and parent s an nverse then chld s a feature drect dependency predcate: ) ( ) predcate of chld: parent( F, f, f ( f f ). ) Adacency of a feature. Let F be a feature odel, f and f be features n F, then edge s a feature adacency predcate: edge( F, f, f ) ( f f ) U ( f f). Co-dependency of a feature. Let F be a feature odel, f and f be features n F, then sblng s a feature co-dependency predcate: sblng( F, f, f) p F, ( p f) I ( p f ). Indrect dependency of a feature. Let F be a feature odel, f be an ancestor feature, f s a descendant feature, then descendant s a feature ndrect dependency predcate: descendant ( F, f, f) ( P F, f p,..., p p,..., pn f, p, p P, < ), and ancestor s an nverse predcate of descendant: ancestor( F, f, f) descendant( F, f, f). Soltarty of a feature. Let F be a feature odel, f be a feature, then soltary s a predcate that holds true f feature soltary s chldless: soltary ( F, f ) chld( F, f, ). Relaton of a feature. Let F be a feature odel, f and f be features n F, then relaton s a predcate that hold true f a selecton relatonshp between f and f exsts: relaton( F, f, f, R) ( R, R : f f ). The followng predcates can be defned for feature odel coparson: Syntactc equvalence. Let F and F be feature odels. Feature odels F and F are syntactcally equvalent f ther feature sets Φ and Φ are equal: F F Φ = Φ, Φ = { f F }, Φ = { f F }. Seantc equvalence. Let F and F be feature odels. Feature odels F and F are seantcally F F C =, equvalent f ther confguraton sets are equal: ( C ) C { c Φ F () c = true}, C = { c Φ F ( c) = true} Φ Φ Φ. =,,, where, are supersets of Φ, Equvalence. Let F and F be feature odels. Feature odels F and F are equvalent f they are syntactcally and seantcally equvalent: F = F ( F F, F F ) Partal syntactc equvalence. Let F and F be feature odels. Feature odel F s partally syntactcally equvalent to the feature odel F f the feature set of F s a subset of the feature set of F : F F Φ Φ, Φ = { f F }, Φ = { f F }. syn

5 Partal seantc equvalence. Let F and F be feature odels. Feature odel F s partally seantcally equvalent to the feature odel F f the confguraton set of F s a subset of the confguraton set F F C C, C = c Φ, F c = true, C = c Φ F c = true. se of F : { ( ) } { ( ) }, The followng transforatons can be defned on feature odels based on ther equvalence. Unary odel transforatons. Let F and F be feature odels, and T : F F be a feature odel T F F. Then T s: ) Syntactc specalzaton transforaton, f F s partally syntactc equvalent to F. ) Seantc specalzaton transforaton, f F s partally seantc equvalent to F. 3) Syntactc generalzaton transforaton, f F s partally syntactc equvalent to F. 4) Seantc generalzaton transforaton, f F s partally seantc equvalent to F. transforaton such as ( ) Bnary odel transforatons. Let F, F, and F 3 be feature odels, and T ( F, F ) F odel transforaton such as T ( F, F ) F3. Then T s: ) Feature unon transforaton, f F F F = { f f F or f } : be a feature 3 = U F and F 3 s a syntactc generalzaton of F and F. ) Product unon transforaton, f C3 = C U C, where C, C, C3 are product confguraton sets of F, F, and F 3, respectvely, and F 3 s a seantc generalzaton of F and F. 3) Feature ntersecton transforaton, f F 3 = F I F = { f f F and f F } and F 3 s a syntactc specalzaton of F and F. 4) Product ntersecton transforaton, f C3 = C I C, where C, C, C3 are product confguraton sets of F, F, and F 3, respectvely, and F 3 s a seantc specalzaton of F and F. 5) Feature dfference transforaton, f F 3 = F F = { f f F and f F } and F 3 s a syntactc specalzaton of F. 6) Product dfference transforaton, f C3 = C C, where C, C, C3 are product confguraton sets of F, F, and F 3, respectvely, and F 3 s a seantc specalzaton of F. 7) Feature copleent transforaton, f F 3 = F \ F = { f f F and f F } and F 3 s a syntactc specalzaton of F. 8) Product copleent transforaton, f C 3 = C \ C, where C, C, C3 are product confguraton sets of F, F, and F 3, respectvely, and F 3 s a seantc specalzaton of F. 4.. Requreents for executable feature odels Executable feature odels ust capture all propertes of a product lne and addtonally provde the followng servces to ts users: ) The ablty to test syntactc valdty (adherence to foral graar descrpton rules), seantc valdty (adherence to eta-odel of a feature odel), copleteness, and consstency of a odel. ) The ablty to query odel about ts structure. 3) The ablty to query odel about ts explctly specfed propertes (characterstcs). 4) The ablty to reason about odel propertes dervable fro ts explct characterstcs. 5) The ablty to fnd slar features or ther groups (feature patterns). 6) The ablty to perfor odel algebra operatons. 7) The ablty to perfor endogenous odel transforatons (feature odel to feature odel). 8) The ablty to perfor exogenous odel transforatons (feature odel to other odel). 5 Specfcaton of executable feature odels: Functonal Java vs. Prolog 5. Descrpton of executable odels usng Functonal Java Functonal Java ( s an open source Java lbrary that s orented at pleentng the concepts of functonal prograng. The lbrary s ntended for use n producton applcatons and has been thoroughly tested wth ScalaCheck. The functonalty s pleented usng functors,.e. generc classes that serve as wrappers for a functon. An exaple of generc functor defnton s presented below: publc nterface F<A, B> { publc B f(a a); }

6 Ths nterface says that for any two types, A and B, there's a functon f that takes an A-type value and returns a B-type value. When ths nterface s pleented, A and B can be any types, as long as the prograer provdes a functon f that takes the forer and returns the latter. Usng the concepts of functonal prograng, we can descrbe every odellng doan concept (progras, odels, predcates on odels, eta-odels, progra and odel transforatons, etc.) as functons: ) Progra s a functon appng fro a proble doan to a soluton doan F : P S. ) Model s a functon (oracle) that answers to a query whether a provded progra s vald M F : F B, where B s a Boolean value doan. 3) Meta-odel s an oracle that answers to a query whether a provded odel s vald M : M B. 4) Meta-progra s a functon that aps fro a set of progras to a progra MP F, E, f, f E s a ult-set of values, f E : ({ }{ } E M ) F, where { F } s a set of progras, { } :{ E} E s a value selecton functon, and { E} F f M : s a appng functon that aps fro a set of values to a specfc progra (progra selector). 5) Meta-progra of odels s a functon that aps fro a set of odels to a odel. 6) Model of eta-progra s a functon that answers to a query whether a provded eta-progra s vald. 7) Progra transforaton s a functon appng fro progras to progras T P : F F. 8) Model transforaton s a functon appng fro odels to odelstm : M F M F. 9) Meta-progra transforaton s a functon appng fro eta-progras to eta-progras. 0) Model of odel transforaton s a functon that answers to a query whether a provded odel transforaton s vald. ) Model of progra transforaton s a functon that answers to a query whether a provded progra transforaton s vald. An exaple of hgh-level descrpton of soe of odellng doan concepts s presented n Fgure. abstract class DoanDefs<P, S> { F<P, S> progra; // progra: proble > soluton F<F<P, S>, Boolean> odel; // odel: progra > bool F<F<F<P, S>, Boolean>, Boolean> etamodel; // etaodel: odel > bool F<P, S, Boolean> etaprogra; // etaprogra: (proble, soluton) > bool F<F<P, S>, F<P, S>> ptransf; // progra transforaton: progra > progra F<F<F<P, S>, Boolean>, F<F<P, S>, Boolean>> Transf; // odel transforaton: odel > odel F<F<F<P, S>, Boolean>, F<P, S>> Inst; // odel nstantaton: odel > progra F<F<P, S, Boolean>, Lst<S>, F<P, S>> pinst; // (etaprogra, set of solutons) > progra F<Lst<P>, Lst<F<P, S>>, F<P, S, Boolean>> etaprograconstr; // (set of probles, set of progras) > etaprogra } Fgure. Defnton of odellng doan concepts n Functonal Java 5. Descrpton of feature odels usng Prolog Prolog s a logc prograng language orented at developng artfcal ntellgence, expert systes and theore provers. A Prolog progra s descrbed n ters of a Turng-coplete subset of frst-order predcate logc. It conssts of a set of facts over whch a user can query, and a set of axos, or rules, defnng relatons (predcates) between obects. There s only one type data type, the ter. A coputaton s a deducton of consequences of the progra. Soe peratve prograng constructs such as value prntng are also allowed. Furtherore, Prolog has rch capabltes for progra ntrospecton, reflecton, eta-nterpretaton and etaprograng (dynac odfcaton of the Prolog s fact and rule knowledge base). Fgure 3. Feature odel of a cell-phone

7 As an exaple, we consder a cell-phone feature odel [9] (Fgure 3). Each cell-phone ust have an accuulator cell, dsplay, and ay have an optonal wreless connectvty. Wreless connecton ay be pleented usng nfrared or Bluetooth connectons. Selecton of Bluetooth requres lon (Lthu-Ion) battery. Dsplay ay be ether onochroe or color, and the selecton of color dsplay excludes the usage of nca (Nckel-Cadu) battery. Cellphone batteres ay be ether of lon, nh (Nckel-Metal hydrde) or nca type. % Feature odel cellphone : all(alt(wreless), accucell, dsplay). wreless : ore_of(nfrared, bluetooth), requres(bluetooth, lon). accucell : one_of(lon, nh, nca). dsplay : one_of(color, onochroe), excludes(color, nca). nfrared. lon. nh. nca. onochroe. % Addtonal rules one_of(a) : A. one_of(a, B) : A > not(one_of(b)); one_of(b). ore_of(a) : A; not(a). ore_of(a, B) : A; B. all(a) : A. all(a, B) : A, B. alt(a) : A; not(a). requres(a, B) : A > B; not(fal). excludes(a, B) : A > not(b); B. Fgure 4. Executable feature cell-phone odel n Prolog In the Prolog executable specfcaton (Fgure 4) of the cell-phone feature odel, feature dependences are specfed as Prolog rules and soltary features are specfed as facts. Addtonal rules specfy feature selecton rules. The feature odel can be executed by typng the Prolog query cellphone. and the Prolog nference engne wll return a Boolean-valued answer whether the current confguraton of the odel s vald. More rules can be specfed for pleentng odel query and transforaton predcates defned n subsecton Evaluaton Based on the prelnary analyss and research conducted on the representaton and pleentaton of feature odels as well as based on soe ntal experents n the area, we present the coparson of Prolog and Java language capabltes for pleentng executable feature odel specfcatons (see Table ). Table. Coparson of Prolog vs. Java Crteron Prolog Java Supported prograng paradgs Logc prograng, declaratve, etaprograng, peratve (partally) Obect-orented, peratve, functonal (partally, usng Functonal Java), generc Mode of usage Doan-specfc General-purpose Ipleentaton Interpretable Coplable to byte code Type syste None (untyped) Strong Syntax extensblty Easy Not supported Correctness provablty Bult-n Tool-based (e.g., usng ScalaCheck) Lbrares Few; poorly-docuented Many; well-docuented Tool support Large Extensve Code sze Copact Verbose Data representaton Explct (as a fact) or plct (as a rule Explct that plctly descrbes a fact) Pattern atchng Bult-n (usng unfcaton echans) Lbrary-based Meta-nterpretaton Bult-n Supported by Java agents (package ava.lang.nstruent) Meta-prograng Bult-n (usng abolsh and assert predcates) Supported va Java Copler API (package avax.tools) Genercty Meta-varables, eta-rules, eta-logcal Generc class, nterface, ethod declaratons predcates, eta-calls Reflecton Bult n (usng clause predcate) Supported va Java Reflecton API (package ava.lang.reflect) Dynac code generaton Supported Supported Logc nference (reasonng) Bult-n Avalable usng reasonng tools or lbrares (e.g., Jena or Pellet) Standardzaton ISO/IEC 3 Managed by JCP docuents

8 6 Further research: as and drectons We a to develop a fraework general enough to accoodate a wde spectru of odels and etaodels avalable n the software engneerng doan. However, we partcularly focus on feature odels and ther nteracton wth other knds of software odels. Therefore, we forulate our research as and drectons as follows: ) Developent, evaluaton and valdaton of feature odel eta-odels. ) Valdaton of feature odels aganst feature odel eta-odel. 3) Reasonng on feature odels as doan ontologes. 4) Mnng of coon feature patterns (sub-odels) n feature odels. 5) Brdgng feature odels wth other doan odels for pleentng back-forth transforaton. 6) Seralzaton of feature odels for staged confguraton. 7) Feature odel nng fro exstng software artefacts. 8) Ipleentaton of hgh-level operatons on feature odels (feature algebra). 9) Adopton of feature dagra notaton for descrbng eta- or ult-product lnes (fales of related product lnes). 0) Developent of hghly custozable rch nternet applcaton and web servce product lnes usng feature odel and source code generator lbrares. Our future work wll nclude developent and pleentaton of executable odels usng Functonal Java, Jena and DependencyFnder lbrares as well as the developent of feature odel transforaton engne usng Prolog and ts nterface wth Java. The developed tools wll be ntegrated nto the developed feature odellng envronent. Our case studes wll nclude a large nuber of feature odels selected fro the lterature as well as fro the Feature Model Repostory ( 7 Conclusons We have presented a foral descrpton of concepts n odellng doan, provded a foral defnton of feature odels, outlned a odel transforaton fraework and dscussed ts applcaton for testng valdty of odels and eta-odels, forulated requreents for executable feature odels and dscussed specfcaton of executable odels usng Functonal Java and Prolog prograng languages. Our ntal experents show that Prolog can be a language of choce for developng executable feature odel specfcatons. References [] Straeten R., Mens T., Baelen S. Challenges n Model-Drven Software Engneerng. In M.R. Chaudron (Ed.). Models n Software Engneerng. LNCS vol. 54, Sprnger-Verlag, Berln, Hedelberg, 009. [] Bosch J. Desgn and use of software archtectures: adoptng and evolvng a product-lne approach. ACM Press/Addson-Wesley Publshng Co., New York, NY, 000. [3] Lee K., Kang K.C., Lee J. Concepts and Gudelnes of Feature Modelng for Product Lne Software Engneerng. Proc. of the 7th Int. Conf. on Software Reuse (ICSR-7), Sprnger-Verlag, London, UK, 00. [4] Czarneck K., Esenecker U. Generatve Prograng: Methods, Tools, and Applcatons. Addson-Wesley, 000. [5] Daaševčus, R., Štukys, V. Desgn of Ontology-Based Generatve Coponents Usng Enrched Feature Dagras and Meta-Prograng. Inforaton Technology & Control, 37(4), 30-30, 008. [6] Kleppe A., Warer S., Bast W. MDA Explaned. Addson-Wesley, Aprl 003. [7] Kühne, T. What s a Model? In J. Bézvn, R. Heckel (Eds.), Language Engneerng for Model-Drven Software Developent. Dagstuhl Senar Proceedngs 040, Schloss Dagstuhl, Gerany 005. [8] Sedewtz, E. What Models Mean. IEEE Software 0(5): 6-3, 003. [9] Serpelon F., Moraes R., Bonacn R. A se-autoated approach to valdate ontology appngs. Proc. of Int. Conf. on New Technologes of Dstrbuted Systes, NOTERE 00, Touzeur, Tunsa, IEEE, 00. [0] Ahed E. Use of Ontologes n Software Engneerng. Proc. of 7th Int. Conf. on Software Engneerng and Data Engneerng SEDE-008, Los Angeles, Calforna, USA, 45-50, 008. [] Bézvn J., Gerbé O. Towards a Precse Defnton of the OMG/MDA Fraework. Proc. of 6th IEEE Int. Conf.on Autoated Software Engneerng ASE 00, Coronado Island, San Dego, CA, USA, IEEE CS, 00. [] Mens T., van Gorp P. A taxonoy of odel transforaton. Electr. Notes Theor. Coput. Sc., 5, 5-4, 006. [3] Sadlek D.A., Weßleder S. Testng Metaodels. Proc. of 4th European Conf. On Model Drven Archtecture Foundatons and Applcatons, ECMDA-FA 008, Berln, Gerany. LNCS vol. 5095, Sprnger 008. [4] Behl M. State of the Art n Model Transforaton Technology. Ebedded Control Systes, Royal Insttute of Technology, Stockhol, Sweden, July 00. [5] Tratt L. Model transforatons and tool ntegraton. Software and Systes Modelng, 4(), -, 005. [6] OMG. MOF.0 Query Vew Transforaton. OMG Tech. Report, 009. Avalable: [7] Kurtev I. Adaptablty of Model Transforatons. PhD thess, Unversty of Twente, The Netherlands, 005. [8] Kraus A. Model drven software engneerng for web applcatons. Ph.D. dssertaton, Ludwg-Maxlans- Unverstat Munchen, 007. [9] Maen, von der T., Lchter H. Deternng the varaton degree of feature odels. Proc. of 9th Int. Conf. on Software Product Lnes, SPLC 005, Rennes, France. LNCS vol. 374, Sprnger, 005.