USINESS PROCESS MODEL TRANSFORMATION ISSUES The top 7 dversries enountered t defining model trnsformtions Mrion Murzek Women s Postgrdute College for Internet Tehnologies (WIT), Institute of Softwre Tehnology nd Intertive Systems, Vienn University of Tehnology, Austri murzek@wit.tuwien..t Gerhrd Krmler usiness Informtis Group (IG), Institute of Softwre Tehnology nd Intertive Systems, Vienn University of Tehnology, Austri krmler@ig.tuwien..t Keywords: Astrt: Model Trnsformtion, usiness Proess Modeling Lnguges Not lest due to the widespred use of met modeling onepts, model trnsformtion tehniques hve rehed ertin level of mturity (Czrneki nd Helsen, 2006). Nevertheless, defining trnsformtions in some pplition res in our se usiness proess modeling is still hllenge euse urrent trnsformtion lnguges provide generl solutions ut do not support issues speifi to distint re. We im t providing generi solutions for model trnsformtion prolems distint to the re of horizontl usiness proess model trnsformtions. As first step in this endevor, this work reports on the most pressing prolems enountered t defining usiness proess model trnsformtions. INTRODUCTION As ompnies disovered the enefits of usiness Proess Modeling (PM), the use of usiness Proess (P) models moved from luury rtile to n everydy neessity in the lst yers. Menwhile mny ompnies own thousnds of models whih desrie their usiness. Sine usiness hnges over the yers, e.g., usiness to usiness interoperility me up with new inventions in ommunition nd ompnies merge with others, there rises need to keep eisting usiness models up-to-dte nd to synhronize or trnslte them into ontemporry PM lnguge. To filitte these senrios, model trnsformtion tehnique for P models is needed. At the moment muh work is done in the re of model trnsformtions (MTs). The min reserh interest lies on the tehnil spets of MTs, for emple trnsformtion lnguges nd verifition of model trnsformtions. Model trnsformtion lnguges like ATL (ézivin et l., 2005), QVT (OMG, ) or frmeworks for generl purpose progrmming lnguges like Jv provide very good solutions for This reserh hs prtly een funded y the Austrin Federl Ministry for Edution, Siene, nd Culture, nd the Europen Soil Fund (ESF) under grnt 3.963/46- VII/9/2002. : nd :n orrespondenes, thus they seem to e well suited for horizontl trnsformtions s is the se when trnsforming P models. Defining trnsformtion etween ny two PM lnguges, however, is still diffiult tsk s severl domin-speifi prolems remin to e solved. PM lnguges re used for distint purpose, nmely the illustrtion proesses in ompny. So they ll provide very similr onepts to the modeler. ut the prtiulr elements nd ttriutes whih re used to epress onept re more or less different in the PM lnguges. sed on the ssumption tht there eist generi solutions for these often ourring prolems, we re urrently developing frmework whih provides solutions for typil trnsformtion prolems pplied on generi met model whih ontins ll onepts of the prtiipting PM lnguges. To the est of our knowledge there is no work on supporting the definition of trnsformtion prolems in distint domin. The ontriution of this work is n overview of the prolems one is onfronted with when defining model trnsformtions in the re of PM. In first step, we fous on the ontrol flow prt of PM lnguges, s this is perhps the most ritil prt of defining P model trnsformtions. This reminder of this work is strutured s follows. The net setion puts our work into ontet
of relted work. Setion 3 introdues the four different usiness Proess Modeling (PM) lnguges we inspeted, nd in setion 4 we disuss the seven most pressing model trnsformtion issues. The onlusion in setion 5 summrizes this work nd gives n insight into ongoing work. ompres the synt nd semntis - y mens of the met model elements - of the onepts provided in the ontrol flow prt of four different PM lnguges, with speifi fous on the differenes etween lnguges nd how these differenes ffet model trnsformtion. 2 RELATED WORK There hs een nd still is muh reserh on the differenes nd equlities of usiness Proess Modeling nd Workflow lnguges. They ll hve different fous why nd how they nlyzed nd ompred some of the lnguges. Wil vn der Alst et l. onentrted on Workflow Systems nd developed the workflow (vn der Alst et l., ), resoure (Russell et l., 2005) nd dt ptterns (Russell et l., 2004). These ptterns hve een nd re still used to uild or nlyze workflow nd PM lnguges onerning their epressiveness. For emple Wohed et l. (Wohed et l., 2005), (Russell et l., 2006), (Wohed et l., 2006) nd White (White, 2004) inspeted the usiness Proess Mngement Nottion (PMN) nd the UML 2.0 Ativity Digrm (AD) to find out how fr the WF ptterns n e represented in these lnguges, with the im of ssessing the weknesses nd strengths of the PMN nd AD nd its overge of usiness proess modeling prolems. In (Mendling et l., ), EPCs hve een nlyzed with regrd to the representtion of the WF ptterns. Additionlly, n etended EPC, yet nother EPC (yepc) (Mendling et l., 2005) hs een developed whih overs ll WF ptterns. Zhmn et. l developed frmework (Zhmn, 987) whih defines the system rhiteture of n enterprise. He uses the five si questions Wht, How, Where, Who, When, nd Why to hive omprehensive view of the whole enterprise. This frmework hs lso een used to evlute PM lnguges, for emple UML 2.0 in (Ftolhi nd Shms, 2006). Korherr et l. (List nd Korherr, 2006) ompred seven different PM lnguges. Their fous ly on the usiness Proess Contet Perspetive nd they evluted how epressive these PM lnguges re for modeling usiness gols nd metris. The reent work (Störrle, 2006) ompres EPCs nd UML 2.0 AD. The omprison is strutured y synt, semnti nd prgmti of the two lnguges. The entrl question whih is left open in this work is if UML 2.0 AD will reple EPCs in the long run. In our work we fous on wht is importnt to keep re of, in se of trnsforming usiness proess models etween different PM lnguges. So this work 3 USINESS PROCESS MODELING LANGUAGES In the following the four PM lnguges, ADONIS R Stndrd Modeling Lnguge, usiness Proess Modeling Nottion (PMN), Event-driven Proess Chins (EPC) nd UML 2.0 Ativity Digrms (AD), whih we hve inspeted onerning P model trnsformtion issues re desried. The onepts illustrted in the following four met models pture the si ontrol flow prt (s defined y Alst et l. - si ontrol flow ptterns) of eh lnguge. This smll ore prt of eh PM lnguge ws tken to demonstrte the differenes etween these four lnguges onerning model trnsformtion. Inspetions of the remining onepts of the PM lnguges re out of sope of this work. 3. ADONIS Stndrd Modeling Lnguge The ADONIS R Stndrd Modeling Lnguge (OC, 2005) provides different kinds of model types whih over different usiness spets. The P model is used to model the usiness proesses itself, i.e., its ontrol flow spet. Furthermore it is used to integrte the orgniztionl nd the informtion spet. Sine our work fouses on the ontrol flow spet, we onentrte only on the P model (see Fig. ). ADONIS R is grph-strutured PM lnguge, whih implies for emple tht there ould e more thn one end element in proess model. The integrl model element is the Ativity. A sequene of tivities is modeled y mens of the Suessor whih represents the ontrol flow in the ADONIS R P model. To depit proess ll within proess, the element Su Proess Cll is used. The Control Ojets re used to model the flow of ontrol. The ADONIS R P model provides no speil element for modeling merges of lterntive ontrol flows. Furthermore, the deision element - Deision - does not distinguish etween lterntive split nd multiple lterntive split.
ADONIS Stndrd Lnguge usiness Proess Met Model Suessor ond:epression Strt Ativity End usiness Proess Model Flow Ojets Control Ojets lled proess Su Proess Cll Deision Prllel Split Prllel Join (AFN). The FFN is used to mrk the finl of distint flow, tht mens if it is rehed the remining tokens in the proess will proeed. Wheres the AFN mrks the end of the whole proess whih mens if it is rehed the remining tokens in the proess re killed immeditely. The only Ativity Edge we onsidered here is the Control Flow whih is used to onnet the Ativity Nodes to form the flow of ontrol of proess. Su Prllel Ativity Proess Strt End Deision Split Join Suessor 3.3 usiness Proess Modeling Nottion Figure : Prt of the ADONIS R P met model nd the onrete synt 3.2 UML 2. Ativity Digrm The UML 2. AD (OMG, ) is lso speifition of the OMG. The met model in Fig. 2 ontins very smll prt of the UML 2. lnguge, the si ontrol flow elements UML whih 2.0 Ativity oulddigrm e used for modeling P models. The PMN (OMG, 2006) ws primrily introdued y the usiness Proess Mngement Inititive (PMI.org) nd is now finlly dopted speifition y the Ojet Mngement Group (OMG). It hs een designed s grphil lnguge to desrie usiness proess models nd mp them to the usiness Proess Eeution Lnguge (PEL) for We Servies. (IM, ). The met model illustrted in Fig. 3 shows the elements whih re used to model the ontrol flow spet. usiness Proess Modeling Nottion Ativity Edge Ativity Node Ativity referenes Sequene Flow ondition:string usiness Proess Digrm ControlFlow gurd:string Control Node Opque Ation Cllehviour Ation ConnetingOjet FlowOjet referenes Opque Ation ForkNode JoinNode Cllehviour Ation InitilNode Finl Node DeisionNode MergeNode FlowFinlNode Ativity Finl Initil Node AtivityFinlNode Join/Fork Deision/Merge Flow Node Node Finl Control Flow Strt Event End Event Prllel Fork Event Prllel Join Gtewy Deision Tsk Ativity Su-Proess Elusive (XOR) Inlusive (OR) Figure 2: Prt of the UML 2. AD met model nd the onrete synt The Ativity denotes different from ADONIS R nd PMN the whole P model. The entrl element is the Opque Ation whih is used to model the tivities within proess. The Cll ehvior Ation represents the onept of su proess ll. Control Nodes re used to struture the proess. There is Fork Node nd Join Node provided to epress onurrent flow nd Deision Node nd Merge Node to model n lterntive flow. The Initil Node mrks the egin of proess model. The AD differs etween two finl nodes, the Flow Finl Node (FFN) nd the Ativity Finl Node Tsk Su-Proess + Strt Event End Event Deision/Merge XOR OR Prllel Fork/Join + Sequene Flow Figure 3: Prt of the PMN met model nd the onrete synt In the PMN the Tsk is the entrl element of the proess model. The Su-Proess is used to model referene to su proess within proess model. Gtewys re used to depit different flows (prllel, lterntive et.) of the proess. To model the egin nd the end of proess model Events re used. The Core Elements n e onneted y the Sequene Flow to form the proess model.
3.4 Event Driven Proess Chins Event Driven Proess Chins (EPCs) (Keller et l., ) hve een introdued y Keller, Nüttgens nd Sheer in 992. EPCs re silly used to model proesses. We fous on the min elements whih re used to model the integrl nd ontrol flow spet of PM (see Fig. 4). Event-driven Proess Chins EPC usiness Proess Proess Flow Control Flow Ojets referenes Event Logil Opertor si XOR OR AND Funtion Event si Comple AND OR Funtion Funtion AND OR Funtion XOR Comple Funtion XOR Control Flow Figure 4: Prt of the EPCs met model nd the onrete synt The Funtion desries n tivity. It retes nd hnges Informtion Ojets within ertin time. The Event represents P stte nd is relted to point in time, it ould e seen s pssive element ompred to the funtion s n tive element (ompre (Mendling nd Nüttgens, 2003)). To model su proess ll the Comple Funtion is used. The Logil Opertors elements re used to struture the proeed of the P model. EPCs do not provide speifi element to indite the egin nd the end of P model, therefor the Event is used. Event elements re not llowed to e in front of n OR nd XOR element. Funtion nd event elements must lternte in the proeed of the P model nd re onneted vi the Control Flow. Another restrition in EPCs is tht rnhes prllel s well s lterntive must e split nd merged with the sme kind of Logil Opertor. 4 MODEL TRANSFORMATION ISSUES Although we hve tken the ontrol flow spet whih is smll prt of eh PM lnguge nd their desriptions my sound very similr, there re lot of differenes onerning the representtion of onepts. efore introduing the trnsformtion issues themselves we first hve to onsider how differenes etween PM lnguges should e hndled y model trnsformtion. Model trnsformtions im t preserving the semntis of model. Unfortuntely this high mition n not lwys e hieved. If this is not possile, for emple if there is missing orresponding semnti onept, then the net stge of requirements is to void loss of informtion during the trnsformtion. This n e otined y nnotting trget model elements, for emple inserting informtion into nnottion ttriute of n element, for resons of doumenttion or k-trnsformtion. If this is lso not possile then nother lterntive is to sk the user - provide user intertion - to deide wht should hppen in distint se. It n lso hppen tht the trget model must e semntilly enrihed, euse of mndtory elements in the trget met model. In this se new informtion sed on the eisting informtion hs to e reted. The following trnsformtion issues hve een enountered during the definition of trnsformtions etween the PM lnguges introdued in Setion 3. Eh issue is desried y its nme, the prtiipting elements nd the prolem desription. Different kinds of emples re provided to estlish understnding of the trnsformtion prolem. To illustrte some of the solutions, ATL hs een used euse it is one of the most well-known trnsformtion lnguges. The solutions would look different in other trnsformtion lnguges suh s QVT ut the prolems would remin the sme. 4. Deision (Un)Amiguity In ADONIS R there is only one element (Deision) to epress inlusive nd elusive lterntives. In ADs n elusive split is modeled y Deision Node nd the inlusive split y Fork Node with gurd onditions on the deprting Control Flows. PMN nd EPCs provide one distint element for eh onept Inlusive(OR)/Elusive(XOR) in PMN nd OR/XOR in EPCs. The trnsformtion prolem in se of trnsforming ADONIS R models into EPC models is to deide if Deision is used s n elusive or n inlusive split. The distintion n e mde depending on the onditions on the outgoing edges of the Deision in ADONIS R. The min prolem is to deide whether the vlue of the ond ttriute on the deprting Suessors of Deision re elusive or inlusive. In the following the trnsformtion prolem is illustrted y mens of n emple trnsformtion ode in ATL where ADONIS R Deision should e trnsformed to n EPC OR or XOR: rule deision2or{ from: d: donis!deision
((d.outgoing.onditions).ifelusive()) to: : ep!or } rule deision2or{ from: d: donis!deision (not (d.outgoing.onditions).ifelusive()) to: : ep!or } The funtion ifelusive() deides whether the onditions re elusive or not. Unfortuntely there is no strightforwrd implementtion euse there re vrious kinds of elusive onditions. For emple: True/Flse, 0/, X/not X nd ntonyms in generl. One possiility ould e to hek the onditions s words vi n enylopedi tht ontins ntonyms, for emple WordNet (Miller et l., 998). 4.2 Invisile Merger Two of the PM lnguges we inspeted offer the possiility to model merger of Alterntive split impliitly, i.e. without using distint element. In ADONIS R the mergers of flows whih hve een split y Deision re impliitly modeled, there is no epliit merge element provided. In PMN the hoie for modeling n epliit elusive(xor) merger is left to the user. In this se the trnsformtion prolem is to deide on whih position in the proess model n impliit (elusive or inlusive) merge is used (for emple see Fig. 5). On this position n XOR or OR merge must e inserted in the trget model. Pper ssigned Downlod nd print pper yes Well-known uthor? no Updte own CV "Reviewed Ppers Review pper fst Review pper refully Figure 5: Invisile Merge in ADONIS R Pper reviewed esy in se of lok-strutured models. ut if we re fed with PM lnguge whih llows the modeling of grph-strutured models s it is the se in our four lnguges, then this lgorithm provides only prtil solution. A more powerful solution pproh for this n e found in (Murzek et l., 2006). 4.3 Mndtory Events In EPCs Events re mndtory. It is required tht efore nd fter funtion there must e n Event, i.e. tht Events nd Funtions hve to lternte during the flow of the proess model. A further restrition in EPCs is, tht it is not llowed to model n Event whih is followed y n XOR or OR element (see semntis of EPCs in (Keller et l., ) nd (Mendling nd Nüttgens, 2003)) There is no semntilly orresponding element in ADONIS R. In PMN (Intermedite Events) s well s in AD (Reeive nd SendSignl) there re events speified. ut the onept of events in PMN nd AD differs from the onept of the Events in EPCs. In EPCs the Events re usiness sttes, mening tht proess is in distint stte, furthermore the events re used to mrk the egin nd the end of proess. In PMN nd AD events represent eternl triggers whih ould e used to model eternl influenes or intertion with the proess. As the events in PMN nd AD ould e ssigned to n intertion spet of PM they hve not een tken under onsidertion in this work. Ativity Strt End The trnsformtion prolem is to deide where to insert Deision events Prllel insplitprllel the proess Join model nd to mke sure tht the trget model is in vlid stte fter the trnsformtion. A possile strightforwrd solution is to onvert for emple n Ativity in ADONIS R into n Event nd Funtion onneted y Control Flow. This would void hving ny Events followed y n OR or XOR. Nevertheless it ould result in invlid EPC proess models. An emple for this prolem is shown y the trnsformtion of the ADONIS R model frgment in Fig. 6 into the EPC model frgment in Fig. 7. A S_ S_ S_ A C The entrl questions to solve this trnsformtion prolem re How to find invisile mergers? nd How to find their orresponding split elements?. One suggestion to solve this prolem is n lgorithm whih detets the positions in the model where more thn one Suessor leds into n element. Then the lgorithm must follow ll the ontrol flow kwrds until it finds ommon split element. This is S C S Figure 6: Strt with following Deision in ADONIS R The model in Fig. 7 violtes the synt of EPC new OR ) )
Ativity Strt End Deision Prllel SplitPrllel Join or Strt erfolgte durh? y y S OR Figure 7: Invlid EPC model - lternting Event/Funtion ondition violted A nd models in two wys. First there is n Event followed y n OR split nd seond the sme is followed y three Events, ut it is mndtory tht Events S () nd Funtions lternte during the flow of the proess model. So this solution is only C prtilly stisfying nd review y the modeler is neessry. S A C Workround or Rüktrnsformtion () soure () trget Figure 8: Possile solution in AD for multiple strt ojets S_ in PMN or A Strt erfolgte durh? y y y S_ The model Workround trnsformtion yle in Fig. 9 shows + S_ nother prolem C resulting from workround or neessry when trnsforming n AD model prtywith two y Triggered y? () Initil Nodes () () into PMN model prt () nd Rüktrnsformtion () soure () trget k gin (). The model in Fig. 9() is semntilly A equivlent ut synttilly different from the model prt in Fig. 9(). new OR Triggered y? y 4.4 Different Strt Ojets In AD, PMN nd EPCs it is possile to define multiple strt ojets for one proess model. ut the semntis of multiple strt ojets is different. In AD ll Initil Nodes will e tivted if the proess strts. This mens tht the Initil Nodes themselves mrk the eginning of proess ut do not depit ny events whih trigger the proess. y ontrst the tivtion of one of the Strt Events in EPCs or PMN is suffiient to trigger the egin of the proess. However the semntis of multiple Strt Events in PMN hnges if ll of the outgoing flows of these Strt Events re leding to the sme Ativity whih implies Prllel Join in front of the Ativity. Then the proess strts, if ll of the Strt Events re tivted. In ADONIS R only one ommon strt element is llowed. This leds to two different semntil prolem res:. The differene in the semntis of strt ojets in AD ompred to the strt ojets in other PM lnguges nd 2. The different semntis of multiple strt ojets. In se of multiple strt events with n elusive lterntive semntis in PMN (see Fig. 8()) it is possile to rete one ommon Initil Node in the AD trget model with proeeding Deision Node (see Fig. 8()). The Deision should e nnotted with ondition tht heks for the trigger of the proess. This workround preserves ll of the informtion nd s muh of the PMN semntis s possile. When trnsforming n Ativity in AD k to PMN this workround needs to e tken into ount suh tht the originl model n e reonstruted. nd ) () soure C + () trget/soure () trget Figure 9: Different model struture AD () t k trnsformtion from PMN () 4.5 Split/Merge Unmiguity This prolem hs een onsidered in our work euse t first sight the provided Logil Opertors (LO) in ll four PM lnguges seemed to e equivlent ut the solution is not trivil : trnsformtion. In EPCs there is only one element used to depit splits nd mergers for distint LO. In PMN it is the sme, eept for the prllel fork nd join there re two different elements. The prolem in se of models of these PM lnguges is to deide whether LO is the egin or the end of rnh of the ontrol flow in proess model when trnsforming to lnguge whih requires to mke tht distintion. One more the Control Flow elements - leding to or deprting from LO - hve to e tken into onsidertion. Three different ses n e distinguished:. LO with one inoming nd more thn one outgoing Control Flows, 2. LO with more thn one inoming nd one outgoing Control Flow nd 3. LO with more thn one inoming nd outgoing Control Flows. In se of () we hve to trnsform it into split ojet. In se of (2) the LO hs to e trnsformed to join or merge ojet. In se of (3) the AND Opertor
hs to e split into three elements: one split element (Prllel Split in ADONIS R, Prllel Fork in PMN nd Fork Node in AD) nd one join/fork element (Prllel Join) onneted y ontrol flow edge. If the LO is n XOR then the trnsformtion leds to one Deision element with more thn one inoming nd outgoing Suessors in se of ADONIS R nd PMN nd to three ojets, Merge Node, Control Flow nd Deision Node in AD. The following ATL trnsformtion ode emple defines the ove solutions for trnsformtion from EPC to ADONIS R : rule nd2prllelsplit{ from : ep!and (.inoming->size() = nd.outgoing->size() > ) to ps: donis!prllelsplit(...) } rule nd2prlleljoin{ from : ep!and (.inoming->size() > nd.outgoing->size() = ) to pj: donis!prlleljoin(...) } rule nd2prlleljoinsplit{ from : ep!and (.inoming->size() > nd.outgoing->size() > ) to psp: donis!prllelsplit(...), su: donis!suessor(...), pjo: donis!prlleljoin(...) } The trnsformtion in the reverse diretion my e optimized to reestlish the originl model. In this se orresponding trnsformtion to the nd2prlleljoinsplit rule, whih merges Prllel Split, Suessor nd Prllel Join to n AND element, hs to e found. As rule in ATL n only mth one element in the from prt this will require more omple solution lgorithm in ATL. 4.6 Join Speifition Prolem This prolem n only e oserved in ADs. Contrry to ADONIS R, PMN nd EPCs whih provide possiility to epress inlusive lterntive merge in ADs there is no semntilly orret wy to depit suh mergers. So the prolem is how to epress inlusive lterntive merge in ADs. In (White, 2004) possile ut s per (Wohed et l., 2005) inorret (in terms of the semntis of n eeutle workflow model) ttempt to over n inlusive lterntive merge in ADs hs een mde (see Fig. 0). In this solution the prolem of the trnsformtion definition lys on the derivtion of the Join Spe epression, whih ould e derived from the deprting edges of the orresponding inlusive lterntive split. The ATL trnsformtion ode for this emple is to omprehensive to illustrte it here.. {Join Spe = A or } A Figure 0: Inorret ttempt to pture synhronising merge - Figure tken from (Wohed et l., 2005) Another lterntive would e to sk the user to deide how to trnsform this prolem. P models re not designed for eeuting them diretly. They re used to support the understnding of usiness proesses nd furthermore they n provide n dequte doumenttion of the usiness proesses in ompny. Therefore the solution in Fig. 0 n e stisfying for usiness people. 4.7 Different Finl Nodes Ation CllehviourAtion Ativity Finl Initil Node Join/Fork Node Deision/Merge No AD provide the possiility to model different kinds of end nodes, the Ativity Finl Node (AFN) nd the Flow Finl Node (FFN). The semntis of these nodes is s follows: When FFN is rehed the remining tokens in model will sueed. In ontrry if the AFN is rehed ll remining tokens in the proessed will e killed immeditely. In the other PM lnguges the end element is used orresponding to the FFN. There is no semntilly equivlent to the AFN. The prolem regrding the FinlNodes in AD is to deide how to trnsform the AFN. A FFN n e trnsformed into n end element in either of the three PM lnguges. ut if n AFN is trnsformed into n End element in ADONIS R, PMN or EPC the semntis of the proess model is different. There re two supposle solutions: First n nnottion of the end ojet in the trget lnguge if n ttriute for nnottions is provided. Seond the retion of n dditionl Ativity, Funtion or Tsk whih is lled Terminte proess nd whih is integrted in front of the end ojet. 5 CONCLUSION In this work there hve e introdued trnsformtion prolems oserved t defining model trnsformtions etween four PM lnguges. Although we only foused on the trnsformtion of the si ontrol flow spet of four PM lnguges we enountered seven non-trivil prolems. As they re similr etween different PM lnguges we suggest to provide generl solutions for often rising prolems. This will redue the effort of defining P model trns-
formtions nd the numer of times tht some of these wheels hve to e reinvented. The trnsformtion issues illustrted n e tegorized into two different res:. Trnsformtion requirements whih rise prolems t the implementtion level, they hve tehnil ompleity, for emple the Deision (Un)Amiguity nd the Invisile Merger prolem. 2. Trnsformtion requirements whih rise prolems onerning their fesiility re situted t the pplition level, they ontin pplition ompleity, for emple the Different Finl Nodes nd the Join Speifition Prolem. The tehnil ompleity ffets model trnsformtion lnguges themselves. Generl trnsformtion lnguges like ATL (ézivin et l., 2005), QVT (OMG, ) or progrmming lnguges like Jv provide very omprehensive ut unspeifi possiilities to define suh trnsformtions. Unspeifi in the sense tht they provide lnguge to define everything ut nothing in speil. The prolems on the pplition level re of oneptul nture nd so they ould hrdly e solved with tehnil inventions. ut there n e provided seond level mehnisms like user intertion whih does not solve the prolem, ut supports the user t trnsformtion. The dversries on the tehnil level n e ttked, for emple y providing reusle generl solutions for distint prolems in the re of P model trnsformtion. REFERENCES ézivin, J., Jouult, F., nd Touzet, D. (2005). An Introdution to the ATLAS Model Mngement Arhiteture. Tehnil report, LINA. OC (2005). ADONIS 3.7 - User Mnul III: ADONIS Stndrd Modeling Method. OC Ltd. Czrneki, K. nd Helsen, S. (2006). Feture-sed survey of model trnsformtion pprohes. IM Systems Journl, pges 62 645. Ftolhi, A. nd Shms, F. (2006). An investigtion into pplying uml to the zhmn frmework. Informtion Systems Frontiers. IM. usiness Proess Eeution Lnguge for We Servies version.. IM. Keller, G., Nüttgens, M., nd Sheer, A.-W. Semntishe Prozeßmodellierung uf der Grundlge Ereignisgesteuerter Prozeßketten (EPK). Tehnil report, Institut für Wirtshftsinformtik Universität Srrüken. List,. nd Korherr,. (2006). An evlution of oneptul usiness proess modelling lnguges. In SAC 06: Proeedings of the 2006 ACM symposium on Applied omputing. Mendling, J., Neumnn, G., nd Nüttgens, M. Towrds Workflow Pttern Support of Event-Driven Proess Chins (EPC). In Proeedings of the 2nd GI Workshop XML4PM t the th GI Conferene TW 2005. Mendling, J., Neumnn, G., nd Nüttgens, M. (2005). Yet nother event-driven proess hin. Mendling, J. nd Nüttgens, M. (2003). EPC Modelling sed on Impliit Ar Types. In Proeedings of the 2nd Interntionl Conferene on Informtion Systems Tehnology nd its Applitions (ISTA). Miller, G. A., Fellum, C., nd Tengi, R. (998). Wordnet: A leil dtse for the english lnguge. Murzek, M., Krmler, G., nd Mihlmyr, E. (2006). Struturl ptterns for the trnsformtion of usiness proess models. EDOCW 06, pges 8 28. OMG. MOF QVT Finl Adopted Speifition. Ojet Mngement Group. OMG. UML 2. Superstruture Speifition. Ojet Mngement Group. OMG (2006). usiness Proess Modeling Nottion Speifition. Ojet Mngement Group, http://www.pmn.org/. Russell, N., ter Hofstede, A. H. M., Edmond, D., nd vn der Alst, W. M. P. (2004). Workflow Dt Ptterns. Tehnil report, Queenslnd University of Tehnology. Russell, N., vn der Alst, W. M. P., ter Hofstede, A. H. M., nd Edmond, D. (2005). Workflow resoure ptterns: Identifition, representtion nd tool support. In Proeedings of the 7th Conferene on Advned Informtion Systems Engineering (CAiSE05). Russell, N., vn der Alst, W. M. P., ter Hofstede, A. H. M., nd Wohed, P. (2006). On the suitility of uml 2.0 tivity digrms for usiness proess modelling. In APCCM 06: Proeedings of the 3rd Asi-Pifi onferene on Coneptul modelling. Störrle, H. (2006). A Comprison of (e)epc nd UML 2 Ativity Digrms. In EPK 2006 Geshäftsprozessmngement mit Ereignisgesteuerten Prozessketten. vn der Alst, W. M. P., ter Hofstede, A. H. M., Kiepuszewski,., nd rros, A. P. Workflow Ptterns. Distriuted nd Prllel Dtses. White, S. A. (2004). Proess Modeling Nottions nd Workflow Ptterns. PTrends. Wohed, P., vn der Alst, W. M., Dums, M., ter Hofstede, A. H., nd Russell, N. (2005). Pttern-sed Anlysis of UML Ativity Digrms. In Proeedings of the 25th Interntionl Conferene on Coneptul Modeling (ER 2005). Wohed, P., vn der Alst, W. M., Dums, M., ter Hofstede, A. H., nd Russell, N. (2006). On the Suitility of PMN for usiness Proess Modelling. In Proeedings 4th Interntionl Conferene on usiness Proess Mngement. Zhmn, J. A. (987). A frmework for informtion systems rhiteture. IM System Journl.