Oconteudodopresenterelatorioedeunicaresponsabilidadedo(s)autor(es). (Thecontentsofthisreportarethesoleresponsibilityoftheauthor(s).) PauloBarthelmessandJacquesWainer RelatorioTecnicoDCC{95-27 WorkowModeling Dezembrode1995
PauloBarthelmessandJacquesWainer WorkowModelingy claimismadethatmorethanonemodelview(orrepresentation)isneededinordertograsp lationshipbetweendata,functionandcoordinationaspectsoftheprocessisdiscussed,anda thecomplexityofprocessmodeling. supportingasynchronouseventsandbatchactivities,matchedbypowerfullrun-timesupport. Adiscussionofworkowmodelsandprocessdescriptionlanguagesispresented.There- Thebasisofanewmodelisproposed,showingthatmoreexpressivemodelscanbebuiltby Abstract thepowerofthesystemasawhole.theabsenceofrulesfordealingwithasituationgeneratesan moreexpressivemodelslessenprocessingeort. executeworkowprocessesthroughtheexecutionofsoftwarewhoseorderofexecutionisdrivenby acomputerrepresentationoftheworkowprocesslogic"[wmc95]inasharedenvironment. 1Introduction Ifwecouldexpressmoreatmodellevel,lesseortwouldbespenttreatingthosesituationsas \uncertaintylevel"thatdemandsextrainformationcollectionandprocessing[gal77].therefore, Workowmanagementsystemscanbedenedas\systemsthatcompletelydene,manageand [BW95],forcingtheseeventsandactivitiestobetreatedasexceptions.Wewillproposeamodelthat exceptions.infact,theywouldstopbeingexceptions,andbecomerule. Animportantpartoforganizationseortsisdevotedtoexceptionhandlingchores[Saa94,SM89]. Theexpressivepowerofthemodelthatdrivesthesystem'sexecutionwillultimatelydetermine arecommonplace,wefeelthatbettermodelscanbebuiltbybeingabletosupportthem. addssupporttosucheventsandactivities.becausebothasynchronouseventsandbatchactivities Mostdescriptionlanguagesarenotabletodepictasynchronouseventsandbatchactivities Businessprocessesneedtobeabstracted,sothattheycanbeautomatedbyaworkowmanagement thatinordertobeuseful,aworkowsystemmustoerbetterrun-timeexceptionhandlingsupport. model,thataimatbuildingmoreexpressivemodels. 2Descriptionlanguages Evenverypowerfulmodelsarenotenoughtocopewiththedinamicsofexecution.Weclaim system.thisabstractionconstitutesamodel[ew94],builtbyanalyzingtherealworldanddepicting someofitsaspectsinadescriptionlanguage.theanalysisprocessisheavilyinuencedbythis Wewillnowdiscussworkowmodelingissuesingeneralandfollowwiththespecicsofanew Portugal,Sempember1995. ythispaperwaspulishedattheproceedingsofcyted-ritosinternationalworkshopongroupware,lisbon, 1
allthedetailsrequiredatenactmenttime.anadditionalsemantic,thatwewillcallrun-time whichthesystemdoesnotwork. support,alsogovernsthemodelexecution,providingadditionaltoolsandfunctionalitywithout language.itsconstructs(thebasicelementsandagrammartocombinethem)willshapethemodel, makingithardtodealwithconceptsleftothemodel.themodelbyitselfisnotabletospecify makingiteasiertoexpresssomeoftheconceptsinaspecicway,whilebarringothers. istosaythatthesystemwillhaveanunderstandingonlyofthosethingsthatcanberepresented, Modeling Workowsystemmodelscouldthereforebeanalyzedwithinthefollowingdimensions: Thesemanticsofthemodelwillgovernitsworkings,beitatsimulationorenactmentlevel.That 2.1Modeling Representation Robinsonwarnsusthatorganizationalmodelingisnoeasytask.Organizationsarenormallycomprisedofmanydierentsemanticcommunities,eachwithitsownspecializedlanguageandworld Run-timesupport Inthefollowingsections,we'llanalyzeeachoftheseitemsinturn. Semantics views[rb91]. nothaveanobjectiveofitsown.itisaprerequisitefortheorganizationtoreachit'srealobjectives.coordinationestablishesrelationshipsbetweenactivitiesandtheirproducts,\bindingtasks intolarger,meaningfulwholes"[hol88].thisdenitionconformswiththatofbannonandschmidt systemmodelsmustaddtothat,includinganewaspect,thatofcoordination.coordinationdoes thanalgorithms"[rob93]). 2.1.1Whatneedstobemodeled Modelsproducedbycurrentsystemanalysisnormallycomprisedataandfunctionmodels.Workow representfaithfullyanyreality,butcanneverthelessbeofhelp(\proceduresaremorelikeadvice Onemustkeepinmindthatmodelsarebutmapsandrecipes,thatinasimilarwaydonot structuredconceptsandpractices. nationrepresentationbringstolightmanynewproblems,asitcorrespondstomuchmoreuid,less content,thatis,processespertainingtotheproductionofaparticularproductorservice".coordi- [BS91],thatsaysthat\Cooperativeworkisconstitutedbyworkprocessesthatarerelatedasto RolesInordertobeabletodistributetaskstotheirperformers,aworkowsystemmusthave Workowmodelingaddstothistraditionalprocesssomenewingredients:rolesandsynchronism. exist(e.g.structuredanalysis[yourdon],ooa[sm92])andareusedtotrytocapturerealityaspects. usingsometraditionalanalysismethod. organizationalrolesknowledge.thisknowledgeisnotnormallynecessarywhenoneismodeling Modelinghasalonghistory,atleastaslongasthatofcomputers.Manyanalysismethodologies theburdenofdeterminingwhichtaskpertainstowhichactornormallylaywiththeusers. willbetrainedtoknowwhat,whenandhowtoaccesseachofthesystemfunctions.inthiscase, therightpersons,automaticallyorwiththehelpofahumanagent.inordertobeabletodistribute Workowsystems,onthecontrary,arebuilttodealspecicallywiththedistributionofworkto Asystembuiltaccordingtotraditionalmethodsnormallytakesforgrantedthatitsoperators 2
work,thesystemmusthavesomeknowledgeoftheorganizationalstructure,hierarchical(lineunits), chronizationofactivities.whenusingtraditionalsystems,usersmustndsomewayofcoordinating enactmenttimetoassignactorstorolesandforinformationandactivityaccesscontrol.usingthis model,onecandescriberolesrelativelytootherroles,asforinstance\thesecretaryofthemanager", \themanageroftheinitiator",\theprojectleaderoftheproject",\themembersofthecommittee" asdoneinthewoorkssystem[alp+94]. SynchronismAnotherissuethatisinmostsystemslefttobedealtwithbytheusersisthesyn- functional(projectandcommittees),rolesandactors.thisorganizationalmodelwillbeusedat beusedtowarnotherparticipantsthatsomeactivitymustbeexecuted. theireorts,perhapsbyestablishinganadditional(manual)protocol.thisextraprotocolwillthen thesystem.inadistributedsharedenvironmentsuchasoces,coordinationofactionsofthemany synchronismisusuallythecentralfocus,andthenecessaryprotocolisautomaticallysupportedby parallelandwhichmustnecessarilybepostponeduntilsomeothersarecompleted. lackofwaysofspecifyingitusingordinarydiagrams(dfds,forinstance).inworkowsystems, Synchronismestablishesactivitydependencies,andspecieswhichtaskscanbeexecutedin 2.1.2Modelscope Workowsystemsscopeisnormallygreaterthanthatoftraditionalsystems,astheymust(toa playersisessentialifbusinessobjectivesaretobereached. Traditionalsystemanalysisisnormallynotconcernedwithsynchronism,asattestedbythe greaterorlesserdegree)supportnotonlystructuredautomatableactivities,butalsounstructured andmanualactivities,thosethatlackanalgorithmicsolution. useoftools(automatedornot)inordertoexpeditetheirwork.thesetoolscouldbespreadsheets, texteditors,databasemanagers,custommadeprograms,orforms(electronicornot),thatwillbe usedtomodifyinformationstoredinpossiblymanydierentdocumentsthatcarrydataconcerning acase. activitiesinvolvedintraditionalanalysiswillcontinuetoberelevant. tionalsystemsplusthecoordinationaspects.datamodeling,functionandeventanalysisandother Thefocusofworkowsystemsarethehumansresponsibleforactivities,thatwilleventuallymake willalwaysbeharderthanthatofbuildingatraditionalsystem,asthecoordinationaspectshave tobeaddedtothedescriptionoftheworkitself.eventsappeartobethebindersofthetwoviews, astheyabstractrealworldincidents\thattellusthatsomethingismovingtoanewstate"[sm92]. Thesemovementindicationsareimportantbothfordatatransformationfunctions(theworkitself) asforthecoordinationofwork. Onemustrealizethatworkowsystemswillnormallyhavetodealwithallelementsoftradi- Workowsystemsareextensionsoftraditionalsystems.Theworkofmodelingsuchasystem bedepictedwithjustone(simple)diagram.3 representationintheirmodels,notbecausedataisnotimportantinworkowsystems,butbecause theemphasisisonthecoordinationaspects. (forexamplediagramsanddatadictionaries).itisthereforeunlikelythatworkowsystemscould dierentkindsofrepresentations,thatwhentakentogetherwouldgiveapictureoftheprocessasa whole.traditionalsystemanalysisoftenproducesmanyandsimultaneousformsofrepresentation Ananalysisofexistingworkowsystemsshowsthatmostofthemdonottrytoincludedata Wefeelthateachofthedierentaspects(data,functions,coordination)shouldbemodeledusing
2.1.3Meta-models Eachworkowsystemisbaseduponameta-model,beitexplicitorimplicit[EW94,EN93].This meta-modelisareectionofthesystemcreatorsviewsofhowspecicmodelsshouldbebuilt.the meta-modeloersamethodologicalbackbone,uponwhichspecicmodelsarebuilt.description tendtobecometorigid,beingincompatiblewiththeformworkisreallydone[such87]. onhowuseractionsshouldbeconducted[ew94]. explicitmodel,buthaveanimplicitonenevertheless,astheirfunctionalityisbasedinassumptions instancethosebasedina\language/actionperspective"[win86],basedinthespeech/acttheory [Sea69],likeTheCoordinator[Win88]andActionWorkow[Med92].Othersystemsdonothavean followmeta-modelguidelines. languagesreectthemeta-model,oeringconstructionsthatmakeitsimpletocreatemodelsthat Modelsthatoverspecify,determininginatoorigorouswaythetemporalsequencingofactivities Somesystemshaveanexplicitmeta-modelandarebasedinsomewellgroundedtheory,asfor Visuallanguagesareemployedbymostworkowsystemsforprocessdescription,probablybecause 2.2Representation theyoerawaytoshieldusersfromdetailsoftheformalismitisbasedupon.we'llassumefrom LookSchlaerandMelloroerusalistofappearancerequirementsforadescriptionlanguage [SM92]: 2.2.1Basicrequirements nowonthatthedescriptionswillalwaysbevisual. Noneedlessdierences(fromexistinglanguages)-ifanappropriatelanguagealreadyexists, Hand-drawable/Nodelicateplacementsneeded-oneshouldbeabletobuildmodelswith nothingmorethanpencilandpaper.thisisessentialasmanytentativeversionsmustbe developedbeforeallthedetailsareinplace.thesketchesaremostofthetimeproducedin theeld,awayfromcasetoolsandthelike. importantdetailswillbemissing. oforganizationalprocesses.ifweonlyhaveasinglemodel,eitheritwillbetoocomplexorelse Wesharethenotionthatmultipleviewsarenecessarytodepictsuchacomplexrealityasthat MultipleViews/Densityofinformation-Diagramsshouldbeworthproducing,butnot Inthepresentpaperweareinterestedindiscussingonlyworkowspecicaspects,i.e.,the unreadable. anewoneoughtnottobedesigned. synchronizationmodel.onemustbeforewarnedthough,thatothercomplementingdiagramswould FeelSomemoresubtlerequirementsforprocessdescriptionlanguages(PDL)areestablishedby haveeventuallytobeproduced,encompassingdataandfunctionmodeling. Reinin[Rei92]: formalinitssyntaxandsemantics, basedonintuitiveconcepts, visual, 4
enactable(executable), abletoexpressavarietyofprocessesthatcanbeanycombinationofformaltoinformaland 2.3Semantics abletosupportdynamiciterationofprocesssteps, abletosupportdynamicchangeoftheprocessdescriptions. abletoexpressbothconcurrentandsequentialtemporalrelations, automatictomanualprocesses, Petri-nets[Rei82]seemtobethebasicformalismuponwhichvariationsareintroducedtoexpress modelsemantics.manymodelsdescribetheirsemanticsbyshowingstandardconversionsbetween theirrepresentationandthatofpetri-nets. Petri-netsoroneofitsvariations.Onecanallegedlyexpressmorewithlesssymbols,oncethateach takeworkowsystemsapartfromothersystems. basicsymbolcorrespondstoasub-net. 2.4Run-timesupport Byitself,representationsarenotabletoexpressallthenecessarydetailsfortheuseofasystem. Whatmostoftherepresentationlanguagesdoisthereforetooermeta-levelconstructionsover Petri-netsoerthebasicmeanstoexpresstheessentialsynchronization,thatspecicaspectthat ExceptionhandlingactionsAtenactmenttime,manyspecialsituationsarise,forwhichno behavior.wewillnowexaminesomeofthesefunctionalities. prescribedprocessingexist.wecallthesespecialsituationsexceptions. Extrafunctionalitymustbeaddedinorderforthesystemtobeuseful,duetoworkowdynamic computersystem,oranassignedactoronvacations,forinstance. inhaste.processexceptionsmayalsobecausedbythelackofusuallyavailableresources,abroken decision,forinstance).processexceptionsoccurwhenspecialoperationsarerequiredtoproducean acceptableoutcome.thismayhappenforinstancewhenanurgentrequesthastobeputthrough isincorrectormissing.insomecases,informationisalteredafterithasbeenused(tomakea exceptionsand2)processexceptions.informationexceptionsoccurwhenpartoftheinformation Ecientexceptionhandlingisthereforeoftheutmostimportance. AccordingtoStrongandMiller[SM89],twomainkindsofexceptionsexist:1)information Exceptionsaremuchmorecommonthanthe(ill-chosen)nameimplies[EN93,Saa94,SM89]. redirectionscouldaimatoneofmanyobjectives: ceptionhandlingactions(ehas).exceptionhandlingnormallyinvolvesaredirection.these Loopingbacktoactivitiesthathavealreadybeenexecuted.Thismayhappenwhenincomplete Thenecessarystepstobringtheexceptionalcasetoanacceptableoutcomewillbecalledex- Skippingoversomeactivitiesasmayhappenwhenanspecialurgentcasehastobeputthrough Reroutingtoincludeactivitiesnotpresentintheprescribedow.Onecouldaddsuchactivities orincorrectdataisdetectedatalateractivityandmustthereforebealtered. totheonesintheoworthoseintheowcouldbeabandonedinfavorofnewones,thatare inhaste. moreaptatdealingwiththeexceptionalcase. 5
upwardinthehierarchyforfurtheranalysis.thisisnotaredirectioninthestrictsenseoftheterm, butimpliesinchangesontheresponsibilitylevel.hierarchiesfunctioninthiscaseasadditional theactivities.thisschedulingmaybedoneautomaticallyusingsomealgorithm(round-robin,work conictresolutiontools[gal77]. ActorschedulingAtenactmenttime,roleswillhavetobelledwithrealactors,thatwillperform loaddistribution)ormanuallybyanactor,whensubjectivejudgmentmustbeapplied.someofthe Theexecutionofnonconventionalactionswillimplyinmanyoccasionsinreferringtheworkcase mayneedtotakeplace. chosenactorsmaynotbeavailableatsomemoment,inwhichcaseanenactmenttimereallocation therequester.thisnegotiationmaybeconductedtoironouttaskdetailsandismadebefore theacceptanceortherefusalofthetask.thesystemmustprovidefunctionalitytoassistinthis negotiationprocess,asdoneintheregattasystem[smm+94],thatautomaticallysupportthiskind ofnegotiationpriortothestartofanystage. TimerelatedissuesOrganizationsworkwithdeadlines.Deadlinetrackingmustthereforebe oeredbythesystem:towarnusersofapproachingdeadlines,towarnsupervisorsofoverduework, Theacceptanceofataskbyanassignedactormayinvolvenegotiationbetweenthisactorand Itisnotdesirablethatsomerole/actorsmighthaveaccesstoinformationorcouldexecuteactions andsoon. AccesscontrolSecurityissuessurfaceinmostsystems,andworkowsystemsarenoexception. instancewhenthereisaninconsistencybetweenauthoritylevelsfortaskexecutionandfordocument beyondtheirauthoritylevel. accessunauthorizeditems.theseemingsimplicityofauthorizationmightoersometraps,for necessarydocuments.adierencebetweentheresponsibleactorandtheexecutorsurfaceshere [Joo94]. ToolintegrationActivitiesworkisbestconductedwiththeaidoftools.Thesetoolsmaybe access[as94].theagentmayhaveauthorityenoughtoexecutethetask,butnottoaccessthe Systemsmustoerwaysofassigningpeopleauthoritylevelsandofenforcingthatnoonemay [ALP+94]thatoersexternalapplicationintegrationthroughitsoperatorandinformationmodels. UnstructuredcommunicationCommunicationisnotalwayselectronicandintra-organizational. unstructured,likespreadsheetsandwordprocessorsorhighlystructured,likeforms.workow specicanalysis,complementarytothecoordinationanalysis. relateddataisusuallypresentedbymeansofforms.databaseaccessisdonewiththeaidofforms, thatmimictheirpapercounterparts.thetools,aswellasdatabasestructurearedeterminedby Eventheconductionofelectronicinterchangecouldbenetfromtheexistenceofatool(maybe Phone,fax,mailandothermediaisextensivelyused,bothinsideandoutsideoforganizationsborders.Thesystemmustoerawayofrecordingthemeaningfulcontentsofthesecommunications. basedonspeech/actconcepts)thatwouldhelpaddsemantictotheseinterchanges. Asystemisgreatlyenhancedbyaexibleintegrationoftools,asdonebytheWooRKSsystem process,documentandevenactivitydescriptionswillprobablybecontinuouslychanged.anolder casemaymakenomeaningundernewrules.6 [EK93].Onceoldercasehistoriesmustbekept,someversioningmeansmustbesupported,as Modelsmustbeinconstantevolution,inordertocopewiththechangesintherealworld
3Modelproposal Existingdescriptionlanguagesnormallysupportonlythespecicationoftheorganizationalmain line,i.e.,of\oceproceduresforthemostpredictablenormalcases"[saa94].weaimatcreating ofroutineexceptionscouldbeincorporatedatspecicationlevel,andsupportedatenactmentlevel. handlingandcomponentreuse. amorepowerfuldescription,abletoexpressmorethanstrictlythemainline.thisgoalcanbe forewarn([ew94,as94],forinstance).ourobjectiveistoenhancethemodelsothatthehandling reachedbybetterintegrationofexceptionhandling. 3.1Modeling everypossibleexceptionbeforehand.suchagoalwouldbedestinedtofailure,assomeauthors Wediscussnexthowweintendtoreachtheforementionedgoals,throughbetterexception Wewouldliketostateclearlythatourintentionisnotofcreatingamodelthattriestopredict objects,andactivities.aplanspeciesstatesandthetransitionsbetweenthem,establishingan ordering.itmodelsexclusivelycoordinationrelatedaspects.inaway,theplanspeciesapossible lifecycle[sm92]ofaworkowinstance.aworkowmayhaveoneormoreplans,correspondingto whenpossiblethoseproposedbytheworkowmanagementcoalition[wmc95]. We'llbaseourmodelproposalonthedenitionsofitsconceptualcomponents.Thedenitionsfollow 3.1.1Denitions items,representationofworktobeprocessed.work-itemsareatomic(indivisible)andpresent themainlineandimportantvariations. tivitiesspecifyobjecttransformationfunctions,theworkitself.activitiesarecomprisedofwork- Aprocessdefinitionmodelsthesolutionforabusinessobjective.Itiscomprisedofplans, tuallyexecutethework-items.aroleisasynergisticcollectionofdenedattributes,qualications automatic. trivialsequencingrequirements.activitiescanbeeitherstructuredorunstructured,manualor Theobjects(applicationdata)encapsulatethedataneededduringworkowexecution.Ac- mustbespecied. (e.g.aprinter).activitiesareatomicinthesensethattheyareperformedbyasoleactorandthat theworkitemshavetrivialsequencingrequirements,thereforeinvolvingnocoordinationaspects. Whenmorethanoneroleisinvolved,orsomespecialsequencingmustbeguaranteed,asub-plan and/orskillsthatcanbeassumedandperformedbyanactor,forthepurposeofachievingorganizationalobjectives.anactor(workowparticipant)canbeahuman,aprogramoranequipment Sub-planscorrespondtoahierarchicaldecompositionofaplan,andlikeaplan,specifytransitionsbetweenstates.Eachstateindicatesastageinthelifecycleofaworkowinstance.Eacgeredbytheoccurrenceofevents.Eventsareabstractionsofrealworldincidentsthatsignalstate statecanbeassociatedwithanactivityorasub-plan,tobeactivatedatexecutiontime(likea enactmenttime.workcasesareinitiallycomprisedofinstancesoftheprescribedobjectsandfollow procedurecall)when/ifthestateiseverreached.statesarereachedthroughtransitions,trig- theprescribedplan,executingtheprescribedactivities. changes[sm92].eventscanbegeneratedoutsidethesystem(forinstancethearrivalofordered requiredobjectsortheactivities.thesechangeswillreshapetheworkcasetoconformittothe goods)orinternally,generatedinsideoneoftheexecutingactivities(forinstancewhentheending ofoneactivitytriggersthestartofthenext). Duringexecution,exceptionalsituationsmaycausechangesineithertheplan,thetypesof Workcases(workowprocessinstance)aretheinstancesofaprocessdescriptioncreatedat Eachactivityhasanassociatedrole,thatatexecutiontimewillbelledbyanactorthatwillac- 7
objectsandactivitiescanarisemanytimesduringworkcase'slifetime.astheworkcaseexecution exceptionalsituation.theprescribedplan,objectsandactivitiescan,andprobablywill,bechanged dynamically,duringthelifetimeoftheworkcase.theneedtodeviatefromtheprescribedplan, proceeds,ahistoryisformed,describingthestepstakensofar. Process Description Workcase Objects Objects History Current Plans normallybeusedbyanalystsintraditionalsystems. someprocesses,analysiswillonlyrevealitsgoalsandtheindicationofhowtheyaremostofthe timereached.exceptionswillcausechangesintherequirements,bringingsometimestheneedfora run-timere-analysisandre-planning.workowsystemsmustoeritsuserstoolsthatwouldonly separatelyandwilleventuallyleadtodierentseparatediagramsand/ordescriptions.weconsider Workowsystemsposetheveryinterestingproblemofdynamicallychangingrequirements.For Figure1:ProcessdescriptionxWorkcasecomponents Activities Activities thateachrepresentationshouldfocusonthespecicaspectitistryingtoportray.asinglediagram Inourmodel,eachoftheworkowdescriptioncomponents(plans,objects,activities)isaddressed Current state asynchronous,i.e.,onecannotanticipatetheexactmomentoftheiroccurrence.aswilllaterbe reacttoexternalandinternalstimuli"[har88].someoftheseeventsthatmustbedealtwithare 3.1.2Asynchronouseventsmodeling willmostcertainlynotbeabletocontainalltherelevantinformation:eitheritwillbetoocomplex oritwillnotaddressalltherelevantissues. discussed,dependingonthemomentofoccurrenceofanevent,aradicallydierentresponsemust Workowsystemsarereactivesystems,i.e.,systemsthat\areeventdriven,continuouslyhavingto havetobegenerated. tobetreatedasexceptions,eveniftheyarecommonplace.inthiscase,theadequateresponsewill dependonuser'sknowledgeindealingwiththesituation.moreknowledgeableuserswillprobably dealwithitsuccessfully,butthatmaynotbetrueforlesstrainedones.weintendtollthisgap, supportingasynchronouseventsbothatmodelandenactmentlevel. Mostdescriptionlanguagesarenotabletodepictasynchronousevents.Thiswillforcetheevents 8
handlerscouldbespeciedatthelevelswhereaspecialresponseisrequired. way,i.e.,thatgenericsystemlevelhandlerscouldbespeciedonlyonce,andthatmorespecic processorsystemlevel,dependingontheexistenceofaspecichandlerornot. Eventswouldthereforereceiveapolymorphictreatment.Theywouldbetreatedeitheratactivity, Weenvisionasystemthatwouldletusspecifyasynchronouseventshandlersinahierarchical Wewillexamineinthissectionnotaspecicrepresentation,butsomerepresentationproblems tobedealtwithatexecutiontime.wewilldiscussitshandlinglateron. 3.2Representation wewouldliketosolve.thepicturespresentedarenottobeconsideredasproposedformsof representation.theyarejustillustrative. Evenwithmoreexpressivemodels,agreatdealofunanticipatedexceptionswillcontinuetohave dependonorganizationpolicies. 3.2.1Asynchronouseventsrepresentation Thearrivalofasignalconnectedtoanasynchronousevent,acancelrequest,forinstance,canimpact aworkcaseinverydierentways,dependingonthemomentofitsarrival. Apossibleorderprocessinglifecycleisdepictedingure2.Theactualresponseswouldnaturally workcaseisinatthemomentofsignal'sarrival. Itcouldeasilybeseenthatdierentcoursesofactionaretaken,dependingonthestagethe Let'sexaminesomeoftherepresentationproblemsexhibitedbytheexample: Afairamountofhandlingisinvolved.Itsdirectintegrationinadiagrammaycausethe diagramtobecometoocomplex,speciallyifmanydierenteventsarebeingdealtwith. Figure2:OrderProcessing Thesameresponseappliestomorethanonestate.ForinstanceProductionschedulingand Onoccasion,somecomplexactionarises,forinstance"Takelegalaction".Thiswillmost Waitingforproductionbothelicitthesamereactions. probablyinvolvemanyexpertdecisionsandonthewholethisactioncanspanmonthsoryears. Foralleects,thisactioncorrespondstoacompletelynewworkcase. 9 Order Entry Production Schedulling Waiting Production Production (Proxy) Delivery Invice Generation
State Orderentry ProductionschedulingUndoanyschedulingactions WaitingforproductionRedoschedulingtolleventualgaps Responseatsignalsarrival Delivery Invoicegeneration Decideifproductionwouldbestoppedor continued Ifdecidedtocontinue-storethegoods Storethegoods Takelegalaction usuallyinvolvesgroupingororderingtheworkcasesaccordingtosomecriteriathattakeallworkcases manyindividualworkcasesarebroughttogetherandsueracollectiveaction.thiscollectiveaction 3.2.2Batchactivities Batchactivities[BW95]alsoposesomespecialrepresentationproblems.Inthiskindofactivities, Abort inconsideration.theoutcomeofthisactioncanbeinoneormoredierentdimensions: Establishinganexecutionprecedence-whensomekindofpriorityisestablished.Someworkcaseswillsuerfurtherprocessingbeforeanyothers. Establishinganoutcome-mighthappenforinstancewhenpositionsarelled.Theworkcases thatgradedbestwillbeapprovedandotherswillnot.dierentfurtherprocessingwillbe conditionalsovaries: Actorscheduling-workcasesmightbegroupedaccordingtosomeneededexpertise,orto appliedineachcase. Apointintimeisreached-theworkcaseswillwaittilladeadlineismet.Thisdeadlinecan Individualworkcaseshavetobeputinwaitstatetillthebatch'sstartingconditionismet.This somegeographiccriteria.thegroupswillthenbeassignedtoanactorthatholdstheneeded expertise,orthatservicesthespeciedlocations. 3.3Run-timesupport Aquotaislled-whenapresetnumberofworkcasesarewaiting(e.g.,processbatchesof10 Bymanualintervention-theworkcaseswaittillanactoractivatesthebatch. at8o'clock). ormore) besetonce(e.g.,3rd.ofjanuary,2019),orberepetitive(e.g.,everyfriday,oreverymorning Evenmoreimportantthanbeingabletorepresentexceptionhandlingatthemodellevelistheability 3.3.1Exceptionhandlingactions todealwiththematexecutiontime.thisisimportantbecausemanyexceptionsareunpredictable. 10
ResponsibilityrelatedactionsAlltheactionsinthisgroupcausetheworkcasetobesentto Weenvisionasystemthatwouldoerstandardresponsestobeappliedwhendealingwithexceptions. someotheractor,thatwilleitherdosomeworkorforwarditonceagain. mostgeneral(andpowerful). Theseexceptionhandlingactions(ehas)wouldrangefromthemostspecic(andrestricted)tothe Backtosender-returntheworkcasetoitssender.Thisehacanbeusedtoestablisha Wewillnowtentativelygroupsomepossibleehasinsomedierentdimensions. Backtotheinformationprovider-sendstheworkcasetotheactorthatprovidedsomepiece Forwardtoresponsible-sendstheworkcasetowhoeverisresponsibleforit.Itwillnormally ofinformation.itmightbeusedtorequestdatacorrection. causetheworkcasetobereferredupwardinthehierarchy.thismayhappenwhenanactor ironoutsomedetails. conversationbetweenarequesterandaprospectiveexecutorofanactivity,sothattheymay ActivityrelatedactionsTheactionsinthisgroupcommandthatoneormoreactivitiesbere enactedorthattheirworkbeundone. Forwardto-sendstheworkcasetosomeotheractor(supposedlymoreknowledgeable),tobe Redostaterelatedactivity-commandsthattheactivityrelatedtoastateberedone.The takencareof. doesnothaveenoughauthoritytohandleacase. Loopbacktostate-causestheworkcasetobesentbacktoapreviousstate,toberedone once,indierentstates. statehastobespeciedbecauseaprocessmightemployastandardactivityinmorethan Rollbacktostate-commandsthatalltheworkdonefromthementionedstateonbeundone. Undostaterelatedactivity-commandsthattheactionsappliedinanactivitybeundone. Again,thisactionshouldbeautomatic. Thisactionshouldbeautomatic,i.e.thesystemshouldkeeptrackofthechanges,sothat theycouldbeundone.canbeusedtoundotheeectsofanactivitythatshouldnothave beendoneintherstplace. fromthereon. PlanrelatedactionsTheseactionscausechangesintheplan.Theyprescribethefuturesteps oftheworkcase. Skipstateactivity-causethementionedstatetoimmediatelytriggerthestartofthenext Performsub-plan-performsanexceptionhandlingsub-plan,continuingprocessingfromthe Planchange-determinesthattheworkcaseshouldowfromnowonbasedonanewplan. shouldbeinterrupted.thisactionmaybeusedtoexpeditetheprocessingofaworkcase,when state,withoutexecutingitsownrelatedactivity.iftheactivityhasalreadybeenstarted,it plansshouldbeallowed[as94,smm+94],asfuturestepsmaynotyetbeclear. Thisnewplancanbebroughtfromalibraryorbedesignedfromscratch.Partialorincomplete anactivityistakingtolongandthereforecompromisingadeadline. currentstateonassoonasthesub-plannishes. 11
InfrastructurerelatedactionsAsystemadministratormusthavewaysfordealingwithcommunication,serverorsoftwarefailures.Actionsofthiskindmayforinstanceinclude: Planconstructionwouldbemuchfasterifonecouldbuildanewplanderivingitfromalready 3.3.2Componentreuse Dumpoutofthesystem-ordersthetransferofdatatoothermedia(diskette,paper)sothat Storelocally-intheeventofcommunicationorremoteserverfailures,storethedatalocally, existingones[mcl+92],specializing,modifyingordoingcomposition.thisplanlibrarycouldthen tilltheresourcesarerestored. functionasacommonartifact[rob93],servingasrepositoryofcommonevolutivesolutions,built andrenedbythemanyinvolvedinreachingorganizationbusinessgoals. Oncethesecomponentsreachawidespreaduse,planscouldbedevelopedinahigherabstraction itcanbefurtherprocessedbymeansotherthanthesystem's. functionasameta-language.eachorganizationwouldthenhaveawayofexpressingtheirplans level,usingthecomponentsasbasicbuildingblocks.thisbasicreusablecomponentswillthen usingitsowntailormadeconstructs. eventhandling,bothatthespecicationandexecutionlevels. ownspecic(meta)language. 3.4Dierencestoothertriggermodels wouldinawayallowthesystemtobeextendedbyitsusers,thatwouldeectivelybuildintheir [Joo94],Regatta[SMM+94]andInConcert[AS94])isthatweareconcernedwithasynchronous Themaindierencefromourmodelandothertriggerbasedmodels(e.g.Joosten'sTriggerModel Systemsareoftenusedinwaysitscreatorshadnotdevised[EW94,Rob93].Componentreuse devices. Thisallowustodepictwaitingstatesandproxy(representingexternalevents)inauniformway, eventhoughthesestatesdonothaveanyassociatedactivity,i.e.,theyarepuresynchronization Ourplansshowstatetransitions,andnotactivitytransitionsasmostoftheothermodelsdo. box(performedbyamailcollector)inanindeterminedstate. nextone,\emptyletterbox".thelatterisatimetriggeredbatchactivity.thisleavesmailorder ",andnotthatitishangingbetween"mailanorder"(performedbyaclient)and"emptyletter hangingalone,withnoexplicitconnectionwiththenextactivity. nectionbetweenfollowingactivities(g.3,p.5).the\mailorder"activitydoesnottriggerthe usingstates,onecanmoretrulydepictaworkcasestate,showingthatitis"waitingforcollection Joostenprovidesin[Joo94]averyinterestingexample(ofabatchactivity)thatshowsnocon- Wefeelthatbyusingstates,theowconnectionsaremadeclearer,asshowningure3.By clientfigure3:waitingstateintriggermodel 12 Mail an Order waiting for collection empty mailbox postman
needtobeinvestigated: mentofbettersuitedrepresentationallanguagesandmeta-modelsofworkows.additionalissues Thispaperrepresentsanintermediarystepinourresearchonworkowmodelingandthedevelop- 4ConcludingRemarksandFutureWork Amethodologicalframeworkmustbespecied,encompassingallprocessaspects:data,functionsandcoordination.Foreachaspect,arepresentationmustbedevised.Themethodology Agraphicalrepresentationmustbedeveloped.Thisrepresentationmustbeabletoexpress asynchronouseventsinaneasyway. References Plan,objectandactivityreusetoolshavetobedevised.Thebrowsingofexistingcomponents Theexecutor/responsiblerelationshipsmustbebetterstudied. hastoconductiveofprocessanalysisandmodelconstruction. [ALP+94]Ader,M.,Lu,G.,Pons,P.,Monguio,J.,Lopez,L.,DeMichelis,G.,Grasso,M.A., andconstructionofnewderivedonesmustbemadeinaneasy,exibleway. [BB90]Bullen,C,Bennet,J.\Groupwareinpractice:Aninterpretationofworkexperience," [AS94]Abbot,K.R.,Sarin,S.K.\ExperienceswithWorkowmanagement:IssuesfortheNext Generation,"inCSCW'94,ACM,1994. Vlondakis,G.WooRKS,anObjectOrientedWorkowSystemforOces,Workingpaper. [BW95]Barthelmess,P.,Wainer,J.\WorkowSystems:afewdenitionsandafewsuggestions, [BC88]Bowers,J.,Churcher,J.\Localandglobalstructuringofcomputermediatedcommunication:developinglinguisticperspectivesonCSCWinCosmos,"fromCSCW'88,ACM, 1988. "tobepublishedacmconferenceonorganizationalcomputingsystems(coocs'95), SanJose,CA,1995. MITCenterforInformationSystemsResearch,Cambridge,MA,1990. [EW94]Ellis,C.,Wainer,J.\GoalBasedModelsofCollaboration,"CollaborativeComputing [EK93]Ellis,C.A.,Kedara,K.\DynamicChangewithinWorkowSystems,"TechnicalReport, [Cle90]Clement,A.\ComputerSupportforComputerWork:ASocialPerspectiveontheEmpoweringofEndUsers,"inCSCW'90Proceedings,ACM,NewYork,1990. ReportCU-CS-639-93,ComputerScienceDept.,UniversityofColoradoatBoulder,1993. DepartmentofComputerScience,UniversityofColoradoatBoulder,1993. [EN93]Ellis,C.A.,Nutt,G.J.\ModellingandAnalysisofCoordinationSystems,"Technical [Har88]Harel,D.\OnVisualFormalisms,"CommunicationsoftheACM,31(1988),pp514-530 [Gal77]Galbraith,J.R.\OrganizationDesign,"Addison-Wesley,Reading,MA,1977. Journal,Vol.1,No.1.June1994. 13
[Joo94]Joosten,S.\TriggerModellingforWorkowAnalysis,"in:G.Chroust,A.Benczur, [MCL+92]Malone,T.,Crowston,K.,Lee,J.,Pentland,B.\Toolsforinventingorganizations:Towardahandbookoforganizationalprocesses,"inProc.2ndIEEEWorkshoponEnabling Tchnologies:InfrastructureforcollaborativeEnterprises( [Med92]Medina-Mora,R.\ActionWorkFlowTechnologyandApplicationsforGroupware,"in ProceedingsCON'94:WorkowManagement,Chalanges,ParadigmsandProducts, Oldenbourg,Vienna,Munich,pp.236-247,ISBN3-7029-039706,October1994. [RB91]Robinson,M.,Bannon,L.,\Questioningrepresentations,"inProceedingsoftheSecond [Rei92]Rein,G.L.,\OrganizationDesignViewedasaGroupProcessUsingCoordinationTechnology,"Dissertac~aodePh.D.,UniversityofTexasatAustin,Austin,1992. GroupWare'92,D.D.Coleman,eds,MorganKaufmannPublishers,SanMateo,Califor- [Rei82]Reisig,W.\Petri-nets,"Springer-Verlag,BerlinHeidelbergNewYork,1982. EuropeanConferenceonComputer-SupportedCooperativeWorkESCW'91,sept.1991, Amsterdam,Netherlands,Bannon,L.,Robinson,M.&Schmidt,K.(Editors). nia,165-167. [Rob93]Robinson,M.\DesignforUnanticipatedUse...,"ProceedingsoftheThirdEuropean [SM92]Schlaer,S.,Mellor,S.J.\ObjectLifecycles:ModelingtheWorldinStates,"Prentice-Hall, [SM89]Strong,D.M.,Miller,S.M.\ExceptionHandlingandQualityControlinOceOperations,"WorkingPaperNumber89-16,BostonUniversity,SchoolofManagement, Boston,MA,1989. ConferenceonComputer-SupportedCooperativeWork,sept.1993,G.deMichelis,C. [Sea69]Searle,J.L,\SpeechActs,"CambridgeUniversityPress,Cambridge,1969. Inc.,EnglewoodClis,NewJersey,1992. SimkoneandK.Schmidt(Editors). [Suc93]Suchman,L.\Docategorieshavepolitics?Thelanguage/actionperspectivereconsid- [SMM+94]Swenson,K.D.,Maxwell,R.J.,Matsumoto,T.,Saghari,B.,Irwin,K.\Abusinessprocessenvironmentsupportingcollaborativeplanning,"inCSCW'94,ACM,1994. [WMC95]WorkowManagementCoalition,"Glossary-AWorkowManagementCoalitionSpecication",http://www.aiai.ed.ac.uk:80/WfMC/glossary.html,1995ered,"ProceedingsoftheThirdEuropeanConferenceonComputer-SupportedCooperativeWork,sept.1993,G.deMichelis,C.SimkoneandK.Schmidt(Editors) [Win88]Winograd,T.\WheretheActionIs,"Byte,pp.256A-258,December1988. [Win86]Winograd,T.,\Alanguage/actionperspectiveonthedesignofcooperativework,"in CSCW'86Proceedings,ACM,1986. 14
92-03OntheIrrelevanceofEdgeOrientationsontheAcyclicDirectedTwoDisjointPathsProblem,C.L.Lucchesi,M.C.M.T.Giglio C.L.Lucchesi,T.Kowaltowski RelatoriosTecnicos{1992 92-01ApplicationsofFiniteAutomataRepresentingLargeVocabularies, 92-02PointSetPatternMatchingind-Dimensions,P.J.deRezende,D.T.Lee 92-04ANoteonPrimitivesfortheManipulationofGeneralSubdivisionsand 92-05An(l;u)-TransversalTheoremforBipartiteGraphs,C.L.Lucchesi, thecomputationofvoronoidiagrams,w.jacometti 92-08MaintainingIntegrityConstraintsacrossVersionsinaDatabase, 92-07NewExperimentalResultsForBipartiteMatching,J.C.Setubal 92-06ImplementingIntegrityControlinActiveDatabases,C.B.Medeiros, C.B.Medeiros,G.Jomier,W.Cellary M.J.Andrade D.H.Younger 92-12BrowsingandQueryinginObject-OrientedDatabases,J.L.deOliveira, 92-10ExamplesofInformalbutRigorousCorrectnessProofsforTreeTraversing 92-09OnClique-CompleteGraphs,C.L.Lucchesi,C.P.Mello,J.L.Szwarcter 92-11DebuggingAidsforStatechart-BasedSystems,V.G.S.Elias,H.Liesenberg R.deO.Anido Algorithms,T.Kowaltowski 15
93-02TheHierarchicalRingProtocol:AnEcientSchemeforReadingReplicatedData,NabordasC.Mendonca,RicardodeO.Anido HansK.E.LiesenbergRelatoriosTecnicos{1993 93-04AlexBFSAlgorithmforProperIntervalGraphRecognition,CelinaM.H. 93-05SistemaGerenciadordeProcessamentoCooperativo,Ivonne.M.Carrazana, 93-06Implementac~aodeumBancodeDadosRelacionalDotadodeumaInterface Lucchesi 93-03MatchingAlgorithmsforBipartiteGraphs,HerbertA.BaierSaip,ClaudioL. 93-01TransformingStatechartsintoReactiveSystems,AntonioG.FigueiredoFilho, 93-07EstadogramasnoDesenvolvimentodeInterfaces,FabioN.deLucena,Hans defigueiredo,jo~aomeidanis,celiap.demello Nelson.C.Machado,Celio.C.Guimar~aes Cooperativa,NascifA.AbousalhNeto,AriadneM.B.R.Carvalho 93-10Minimizac~aodoConsumodeEnergiaemumSistemaparaAquisic~aode 93-08IntrospectionandProjectioninReasoningaboutOtherAgents,Jacques 93-09Codicac~aodeSequ^enciasdeImagenscomQuantizac~aoVetorial,Carlos AntonioReinaldoCosta,PauloLciodeGeus Wainer DadosControladoporMicrocomputador,PauloCesarCentoducatte,Nelson K.E.Liesenberg 93-13ModellingGeographicInformationSystemsusinganObjectOriented 93-12Boole'sconditionsofpossibleexperienceandreasoningunderuncertainty, 93-11AnImplementationStructureforRM-OSI/ISOTransactionProcessing PierreHansen,BrigitteJaumard,MarcusPoggideArag~ao Madeira ApplicationContexts,FlavioMoraisdeAssisSilva,EdmundoRobertoMauro CastroMachado 93-15UsingExtendedHierarchicalQuorumConsensustoControlReplicated 93-14ManagingTimeinObject-OrientedDatabases,LincolnM.Oliveira,Claudia Framework,FatimaPires,ClaudiaBauzerMedeiros,ArdemirisBarrosSilva 93-17MetodologiasparaConvers~aodeEsquemasemSistemasdeBancosdeDadosHeterog^eneos,RonaldoLopesdeOliveira,GeovaneCayresMagalh~aes Data:fromTraditionalVotingtoLogicalStructures,NabordasChagasMendonca,RicardodeOliveiraAnido Kowaltowski,EvandroBacarin 93-16LL{AnObjectOrientedLibraryLanguageReferenceManual,Tomasz
93-18RuleApplicationinGIS{aCaseStudy,ClaudiaBauzerMedeiros,Geovane 93-19Modelamento,Simulac~aoeSntesecomVHDL,CarlosGeraldoKrugereMario 93-20ReectionsonUsingStatechartstoCaptureHuman-ComputerInterface CayresMagalh~aes 93-22MinimizationofBinaryAutomata,TomaszKowaltowski,ClaudioLeonardoLucchesieJorgeStol 93-21ApplicationsofFiniteAutomatainDebuggingNaturalLanguageVocabularies,TomaszKowaltowski,ClaudioLeonardoLucchesieJorgeStol LucioC^ortes Behaviour,FabioNogueiradeLucenaeHansLiesenberg 93-23RethinkingthednaFragmentAssemblyProblem,Jo~aoMeidanis 93-24EGOLib UmaBibliotecaOrientadaaObjetosGracos,EduardoAguiar 93-27AUniedCharacterizationofChordal,Interval,IndierenceandOther 93-25Compreens~aodeAlgoritmosatravesdeAmbientesDedicadosaAnimac~ao, 93-26GeoLab:AnEnvironmentforDevelopmentofAlgorithmsinComputational Patrocnio,PedroJussieudeRezende 93-28ProgrammingDialogueControlofUserInterfacesUsingStatecharts,Fabio ClassesofGraphs,Jo~aoMeidanis Geometry,PedroJussieudeRezende,WelsonR.Jacometti RackelValadaresAmorim,PedroJussieudeRezende 93-29EGOLib{ManualdeRefer^encia,EduardoAguiarPatrocnioePedroJussieude NogueiradeLucenaeHansLiesenberg Rezende 17
94-03OAlgoritmoKMPatravesdeAut^omatos,MarcusVinciusA.Andradee 94-01AStatechartEnginetoSupportImplementationsofComplexBehaviour, 94-02Incorporac~aodoTempoemumsgbdOrientadoaObjetos,^AngeloRoncalli AlencarBrayner,ClaudiaBauzerMedeiros FabioNogueiradeLucena,HansK.E.Liesenberg RelatoriosTecnicos{1994 94-06TimesAssncronos:UmaNovaTecnicaparaoFlowShopProblem,Helvio 94-04OnEdge-ColouringIndierenceGraphs,CelinaM.H.deFigueiredo,Jo~aoMeidanis,CeliaPicinindeMello PereiraPeixotoePedroSergiodeSouza ClaudioL.Lucchesi 94-05UsingVersionsingis,ClaudiaBauzerMedeirosandGenevieveJomier 94-10Introduc~aoaosEstadogramas,FabioN.deLucena,HansK.E.Liesenberg 94-09APrologmorphologicalanalyserforPortuguese,JacquesWainer,Alexandre 94-08Reasoningaboutanotheragentthroughempathy,JacquesWainer 94-07InterfacesHomem-Computador:UmaPrimeiraIntroduc~ao,FabioNogueira 94-11MatchingCoveredGraphsandSubdivisionsofK4andC6,MarceloH.de Farcic delucenaehansk.e.liesenberg 94-12UmaMetodologiadeEspecicac~aodeTimesAssncronos,HelvioPereira Peixoto,PedroSergiodeSouza CarvalhoandClaudioL.Lucchesi 18
95-03W3noEnsinodeGraduac~ao?,HansLiesenberg 95-02Adaptiveenumerationofimplicitsurfaceswithanearithmetic,LuizHenriquedeFigueiredo,JorgeStolsional,PedroJ.deRezende,RenatoFileto RelatoriosTecnicos{1995 95-01Paradigmasdealgoritmosnasoluc~aodeproblemasdebuscamultidimen- 95-06GuaranteeingFullFaultCoverageforUIO-BasedMethods,RicardoAnido 95-07Xchart-BasedComplexDialogueDevelopment,FabioNogueiradeLucena, 95-05ProtocolsforMaintainingConsistencyofReplicatedData,RicardoAnido, 95-04Agreedymethodforedge-colouringoddmaximumdegreedoublychordal N.C.Mendonca andanacavalli HansK.E.Liesenberg graphs,celinam.h.defigueiredo,jo~aomeidanis,celiapicinindemello 95-08ADirectManipulationUserInterfaceforQueryingGeographicDatabases, 95-10AHighlyRecongurableNeighborhoodImageProcessorbasedonFunctionalProgramming,NeucimarJ.Leite,MarceloA.deBarros JulianoLopesdeOliveira,ClaudiaBauzerMedeiros 95-11ProcessadordeVizinhancaparaFiltragemMorfologica,IlkaMarinhoBarros, 95-09BasesfortheMatchingLatticeofMatchingCoveredGraphs,ClaudioL. 95-12ModelosComputacionaisparaProcessamentoDigitaldeImagensemArquiteturasParalelas,NeucimarJer^onimoLeite RobertodeAlencarLotufo,NeucimarJer^onimoLeite Lucchesi,MarceloH.Carvalho 95-16AgentesReplicanteseAlgoritmosdeEco,MarcosJ.C.Euzebio 95-15NP-HardnessResultsforTension-FreeLayout,C.F.X.deMendoncaN.,P. 95-14VertexSplittingandTension-FreeLayout,P.Eades,C.F.X.deMendoncaN. 95-13ModelosdeComputac~aoParalelaeProjetodeAlgoritmos,RonaldoParente 95-17AnaisdaIIOcinaNacionalemProblemasCombinatorios:Teoria,AlgoritmoseAplicac~oes,Editores:MarcusViniciusS.PoggideArag~ao,CidCarvalho Eades,C.L.Lucchesi,J.Meidanis demenezesejo~aocarlossetubal 95-18AsynchronousTeams:AMulti-AlgorithmApproachforSolvingCombinatorialMultiobjectiveOptimizationProblems,RosianedeFreitasRodrigues, desouza PedroSergiodeSouza 19
95-22TextStructureAimingatMachineTranslation,HoracioSaggionandAriadne 95-21ALinearTimeAlgorithmforBinaryPhylogenyusingPQ-Trees,J.Meidanis 95-20JohnvonNeumann:SuasContribuic~oesaComputac~ao,TomaszKowaltowski 95-19wxWindows:UmaIntroduc~ao,CarlosNevesJunior,TallysHooverYunes,Fabio ande.g.munuera NogueiradeLucena,HansKurtE.Liesenberg 95-25MultiwarePlataform:SomeIssuesAbouttheMiddlewareLayer,Edmundo 95-23CalculodelaEstructuradeunTextoenunSistemadeProcesamientode 95-24ATIFS:UmAmbientedeTestesbaseadoemInje,caodeFalhasporSoftware,ElianeMartins RobertoMauroMadeira LenguajeNatural,HoracioSaggionandAriadneCarvalho CaixaPostal6065 UniversidadeEstadualdeCampinas 13081-970{Campinas{SP BRASIL reltec@dcc.unicamp.br20 DepartamentodeCi^enciadaComputac~ao IMECC