to Supply Chain Management
Marc-PhilippeHuget
AgentARTGroup
UniversityofLiverpool
LiverpoolL697ZF
UnitedKingdom
Abstract. AgentUMLisagraphicalmodelinglanguagefordescribing
multiagentsystemsbutuntilnow,ithasnotbeenappliedtoreal-world
applications.Theaimofourprojectisto applyAgentUMLtoSupply
ChainManagement.Thisprojecthasseveralobjectives:(1)itallowsus
to discover which diagramshave to be enhanced, modied or created
and,(2)itallows ustodeneamethodologybasedonAgentUMLand
severaltools.Thispapersummarisesourpreliminaryresultsonapplying
AgentUMLtoSupplyChainManagementandgivesanoverviewofthe
UMLdiagramsthatareofparticularinteresttodesignanddevelopment
ofmultiagentsystems.Weconcludewithadiscussionoffutureworkin
thisarea.
1 Introduction
For several years, methodologies and graphical modeling languages have been
suppliedtodesignersinordertodesignsystems,softwareandcomponents.UML
[3] iscertainly thebest known graphicalmodeling language.Forseveralyears,
multiagentsystemdesignershavethesamepossibilitywithsomemodelinglan-
guages like Agent UML [9] [2]. Agent UML is based on UML. As Odell and
Bauerquoted it,itisnotpossibletodirectly useUMLsinceseveraldierences
exist betweenagentsandobjectsliketheautonomyortheabilityto cooperate
[8]. However, it seemsto be important to capitalize onthe skills of designers.
Multiagentsystemdesigners are oftensoftware engineerswhouse UML orare
awareofit.EvenifastronginterestismanifestonAgentUML(seetheInternet
sitehttp://www.auml.orgforpapersonthesubject),atpresent,itdoesnotexist
anapplicationofAgentUMLtoreal-worldapplications.Theonlyexamplethat
wecan give isMOTIV-PTA [1]but this paperdoes notpresent theimpact of
AgentUMLduring thedesign.
Wecurrently leadaprojecttryingto apply AgentUML to the exampleof
Supply Chain Management [10] in order to (1) nd which diagrams in Agent
UML haveto be enhanced, modied orcreated and (2) design methodologies
andtoolsforAgentUML.ThispaperpresentsourrstresultsonapplyingAgent
UMLto theapplication ofSupplyChainManagement.
UMLdiagrams.Alongerversionofthispaperis in[5].
2 Agent UML Diagrams
Asstatedinintroduction,AgentUMLisanextensionofUMLinordertotackle
thedierencesbetweenagentsandobjects.As aconsequence,AgentUMLhas
severalrepresentations:
1. Sequencediagrams
2. Collaborationdiagrams
3. Activitydiagrams
4. Statechartdiagrams
5. Usecasediagrams
6. Classdiagrams
7. Objectdiagrams
8. Packages
9. Componentdiagrams
10. Deploymentdiagrams
Sequence diagrams are used in Agent UML to represent interaction proto-
cols. These diagrams are already modied [9][2] [6]. The application gives us
somefeedbackon what couldbe done:(1)it isimpossibleduring allthe inter-
actiontostopandtopreventabnormalexecution.Thenotionofexceptionsand
triggeringactionsarenotpresent.Such proposalsare givenin [6].Moreover,it
isnotpossibleto linkseveralprotocolstogether.Wedonotspeakaboutnested
orinterleavedprotocolsbutaboutthesideeectofprotocolseachother.Forin-
stance,iftheagentscurrentlyconsider thenegotiationandsimultaneously,the
clientcancelsherorder,therstprotocolisnolongervalid.Itisnotpossibleto
notifythesideeectsbetweeninteractionprotocols.(2)implementingthiskind
ofprotocoldiagrambyhandispainfulanditdoesnotpreventerrors.Designers
needtoolsfordesigningtheirprotocoldiagrams.
Collaboration diagrams and activity diagrams are not considered for the
moment.
Statechart diagrams allow us to represent the dynamic of the system and
particularly,theowbetweenelementsinthesystem.Statechartdiagramscon-
siderthedierentstatesofthesystemandhowtogofromstatetostatethrough
actions.Statechartdiagramsseemtobeaninterestingapproachinordertorep-
resentagents'behaviors.Whenreading statechartdiagrams,readerscanpoint
outthatitisimpossibletoknow(exceptwithnotes)whoisresponsibleforthe
eventsandtowhomtheactionsareaddressed.Themaindrawbackinstatechart
diagramswhenconsideringmultiagentsystemsseemstobetheinabilitytorep-
resentconcurrentactions.Actually,itispossiblethattheorderacquisitionagent
receivesanorderwhilenegotiatinganotherone.
Usecasediagrams representtheuse cases,the actorsand therelationships
between theactors and the use cases.A use case canbe seen asascenarioin
is required.Inmultiagentsystems,usecasesare interestingwhen realizingthe
requirementanalysis.Theyarehelpful during meetings betweenend usersand
designers since they are graphical. It is easier for users to seize the dierent
elementsofthesystem.Themainadvantageoftheusecasesisto focusonthe
what and not onthe how, that is to say on thesystembehaviorand not how
thesystemis implemented.
ClassdiagramsinUMLrepresentthedierentclassesandtheirconnections.
Class diagrams correspond to the architecture of the system. Class diagrams
seem to be interesting in order to represent the dierent agent roles and the
relationsbetweentheroles. Sinceagentsandobjectsarenotexactlythesame,
we think that class diagrams have to be updated in order to consider agent
features like beliefs, intentions, plans or knowledge. UML class diagrams only
consider attributes and operations. A rst proposal of extension of these class
diagramsisin [1].Weenhance thisproposalin[4].
UMLandasaconsequenceAgentUMLallowustorepresentseverallevelof
abstractions when designingclass diagrams.Sometimes it is notinteresting to
haveanaccurateviewofthesystemwith thedependenciesand theattributes.
High-levelclass diagramsallowto seize thesystemin its entirety.We consider
heretwolevels:theconceptuallevelandtheimplementationlevel.Theconcep-
tuallevelisahigh-levelviewofthesystemgettingridofthedetailssuchashow
agentsare implemented or the connected classes. The implementation level is
adetailedviewofthesystemwiththedetailed information.Designerscanalso
denearangeof viewbetweenthesetwoonesaccordingtotheirrequirements.
Class diagrams are central and a lot of details have to be given on class
diagrams. It is not easy to do that without a proper method. It seems to be
importanttohaveamethodologyfordeningtheseclassdiagrams.
Objectdiagramsarenotconsideredforthemoment.Theyallowtorepresent
thesnapshotofinstancesofclassesduringexecution.Theycouldbeinteresting
foravalidationstageifdesignerswanttocheckifatsomemoment,agentshave
aparticularstate.
Component diagrams describe thephysical elements used during run-time.
Componentsrepresent elements accessibleby interfaces. Components are Java
classes,data les,databases,legacysoftware,etc. Previousdiagramspresented
aboveconcernthedesignofmultiagentsystems.Thisdiagramandthenextone
dealwiththedevelopmentofmultiagentsystems.
It seems that component diagrams are required in multiagent systems in
order to perform compilation ofagentsandin order to knowthe dependencies
between elements. Therst use doesnot arise somemissing elementsin these
diagrams.
Deploymentdiagrams are usedto represent themultiagentsystemcongu-
ration at run-time; that is, these diagrams describe how agentsand resources
aredeployedonmachines.
Deploymentdiagramsinterveneattheveryendofthedevelopmentandallow
to describetheneededresourcesand howagentsaredeployed.These diagrams
signersarenotthesame.Deploymentdiagrams representthestaticviewofthe
deployment.Itcouldbeaprobleminthecontextofmobileagentssincetheyare
notabletorepresentthetranslation.
3 Conclusion
Thegraphical modeling languageAgentUML isnowin thetoolboxof multia-
gentsystemdesigners.However,AgentUMLisin itsinfancy andfurthereort
isrequiredinordertoinstantiatecompletelyAgentUMLtothedomainofmul-
tiagentsystems.Untilnow,there isfew workon AgentUML andlessworkon
applying Agent UML to real-world applications. The aim of this paper is to
presentour veryrst results on the application of Agent UML to the Supply
Chain Management example. This example seems to be enough important to
allowdesignerstoseizewhatismissing inAgentUMLandwhat iswrong.
Theapplication ofAgentUML toSupply ChainManagementarisesseveral
questions and highlightssomelacksin thecurrentversionof Agent UML.Nu-
merousdirectionsofresearcharepossible.Wespecicallyfollowthesedirections:
(1)goingdeeperinthedesignofthisapplicationinordertondwhatismissing
in AgentUML,(2) designingtoolsforhandlingAgentUML diagrams 1
and(3)
dening amethodologyforthedesignofdiagrams.
References
1. B.Bauer. UMLclassdiagramsrevisitedinthecontextofagent-basedsystems.In
M.Wooldridge,P.Ciancarini,andG.Weiss,editors,ProceedingsofAgent-Oriented
Software Engineering (AOSE 01), number2222 in LNCS, pages 18, Montreal,
Canada,May2001.Springer-Verlag.
2. B.Bauer,J.P.Muller,andJ.Odell.AnextensionofUMLbyprotocolsformultia-
gentinteraction.InInternationalConferenceonMultiAgentSystems(ICMAS'00),
pages207214,Boston,Massachussetts,july,10-122000.
3. G.Booch,J. Rumbaugh,andI.Jacobson. The UniedModeling Language User
Guide. Addison-Wesley,Reading,Massachusetts,USA,1999.
4. M.-P.Huget.AgentUMLclassdiagramsrevisited.TechnicalReportULCS-02-013,
DepartmentofComputerScience,UniversityofLiverpool,2002.
5. M.-P.Huget.AnapplicationofagentUMLtosupplychainmanagement.Technical
ReportULCS-02-015,Department ofComputerScience,University ofLiverpool,
2002.
6. M.-P.Huget.ExtendingagentUMLprotocoldiagrams.InF.Giunchiglia,J.Odell,
andG.Weiss,editors,AAMASWorkshoponAgent-OrientedSoftwareEngineering
(AOSE),Bologna,Italy,July2002.
7. M.-P.Huget. AlanguageforexchangingAgentUMLprotocoldiagrams.Technical
ReportULCS-02-009,Department ofComputerScience,University ofLiverpool,
2002.
1
A rst steptowards this goal is to dene a format for exchangingdiagrams. For
furtherdetailssee[7].
J.Bradshaw,editor,Handbook inAgentTechnology.MITPress,2000.
9. J.Odell,H.V.D.Parunak,andB.Bauer.ExtendingUMLforagents.InG.Wag-
ner,Y.Lesperance,andE.Yu,editors,ProceedingsoftheAgent-OrientedInforma-
tionSystems Workshop atthe17thNational conference onArticialIntelligence,
Austin,Texas,july,302000.ICuePublishing.
10. J. Swaminathan, S.Smith,and N.Sadeh-Koniecpol. Modeling supplychaindy-
namics:Amultiagentapproach. Decision Sciences,April1997.
