Coordination-theoretic approach to modelling grid service composition process

Journal of Systems Engineering and Electronics Vol. 21, No.4, August 2010, pp.713-720Available online at www.jseepub.comCoordination-theoretic approach to modelling grid servicecomposition processMeng Qianl.*, Zhong Liul , Jing Wang', Li Yao' , and Weiming Zhang'1. School of Information System and Management, National University of Defense Technology, Changsha 410073, P. R. China;2. Institute of Inelligence Equipment, Academy of Air Force Equipment, Beijing 100085, P. R. ChinaAbstract: A grid service composite process is made up of com-department of defence and the open grid service architec-plex coordinative activities. Developing the appopriate model ofture (OGSA) proposed by the global grid forum [2].grid service coordinative activities is an important foundation forConceived by SOC, a system could be constructed withthe grid service composition. According to the coordination theory,reusable services combined with grid services with thethis paper elaborates the process of the grid service compositionby using UML 2.0, and proposes an approach to modelling thegrid service composition process based on the coordination the-nation theory as a sound approach for analyzing complexory. This approach helps not only to analyze accurately the taskprocesses [4,5], this paper presents a kind of top-downactivities and relevant dependencies among task activities, bmodelling approach for the grid service composition withalso to facilitate the adaptability of the grid service orchestrationreference to the similarities and differences of the com-to further realize the conectivity, timeliness, appropriateness andplex process of the grid service composition, namely, someexpansibility of the grid service composition.consideration and exploration on the coordination of theKeywords: process modelling, grid service, service composition,coordination theoapproach are used here to understand and analyze betterDOI: 10.3969/.issn. 1004-4132.2010.04.027the process and coordination mechanism of the grid ser-vice composition, to improve the conectivity, timeliness,accuracy and expansibility of the grid service composi-1. Introductiontion and eventually to integrate efficiently the grid serviceThe US department of defence has put forward five planscomposition.to accelerate the conversion of the service-oriented com-2. Process coordination in the coordinationputation (SOC), falling into ones related with services:theorynet centric enterprise service (NCES), global informa-The research on coordination theory has a consanguineousagement command and control (JBMC2). The service-correlation with that on organization theory, as evi-oriented computation differs from the traditional compu-dences of the organizational coordination theory, inter-tation paradigm in that it involves at least three aspects:organizational relation theory and inter-organizational CO-service providers, service consumers and service brokersordination theory. Solving the collaborative problems[1]. The huge number of the current legacy systems andwithin an organization is involved with the dependenciesthose in process and planned leads to the complexity ofamong them. The inner organizational coordination isthe relations among the services of the global informationtreated as a concentration or integration in which the com-grid (GIG), thus requiring the support of exact, effectiveponents connect with each other for a same goal [6]. Theand fexible methodology for the composition of grid ser-origin of the coordination problems rests with the depen-vices like NCES and GES. Yet, so far the methodologydencies and the uncertainties of task, the conficts amongof the service composition is still on exploration with notarget, the scale of organization, division of works, limitedfinal conclusion in terms of both the GIG offered by the USlogos and uncertainties of environment[7-9].Malone and his colleagues in the Coordination ScienceManuscript received February 18, 2009.Centre of MIT think that the coordination process involves*Corresponding author.This work was supported by the National Natural Science Foundationidentical goals, activities needed to perform to attain goals,of China (70771 109).participants and int中国煤化工with the .YHCNM HG714Journal of Systems Engineering and Electronics Vol. 21, No.4, August 2010focus on how to manage the inter-relations among activ- accomplish the depiction of the generic process and itsities as well as define three types of dependencies: thestandards and on this basis set up the sub-steps for the CO-flow, sharing and ft dependencies [10]. The flow depen-ordination mechanism [15, 16]. The exceptions occurringdency implies demand relations between two coordinative with the coordination mechanism can be treated with ex-sides, with one supplying the desired products to another,ception handlers.e.g., the intelligence production supplying intelligence ap-3. Depiction of the composition based onplication with resources. The sharing dependency repre-coordination theorysents the relation between tasks and desired and dividedresources. For example, the sharing dependency exists be-The grid service system takes the service composition as itstween labour and a task to the coordinative sides in a task.core [17, 18], as shown in Fig. 2. In this system, one ser-The fit dependency indicates the products produced by twovice composition consists of multi-simple services and re-or more coordinative sides and the need to merge those lations between services. Each simple service is composedproducts. Take the activities of reorganizing combat intel- of multi-operations, while those operations are connectedligence, among which exists a fit dependency.through multi-messages. Every operation encompasses theIn accordance with a top-down approach to modellingequipment operation, the operation with people engage-complex activities based on coordination theory developedment and the computable resource operation, in whichby Malone and his colleagues, one determines the processthe equipment operation is linked with the equipment re-by first identifying the core tasks and key dependenciessources, the operation with people engagement with actorsin that process. The next step is to select the coordina- and the computable resource operation with computer re-tion mechanism that will be used to manage each depen- sources. These kinds of link display the dependence ofdency to further decompose the core tasks into subtasks.those operations on the resources. Therefore, equipmentSince the selected coordination mechanism may introduceresources, actors, and computable resources are reduced tonew dependencies and exceptions, they will in turn require resources.additional coordination mechanisms and handlers. ThisBased on the fruit of coordination theory, thedecomposition can continue to any desired level of detailcoordination-theoretic grid service composition process is[11-13].shown clearly in the frame below as regards the grid ser-Through the development of the process itself (orvice system defined in this paper.process depiction and its dependent standard vocabulary(a) The coordination of multi-composed services isdatabase), such as process depiction manual [14], we can viewed as the process.Composed0..、0..nSimpleRelationshipDepend-among servicesncy0..n0.n| MessageMessag|Operation| ActivityEquipmentalArtificial[ Computable resourceoperationObject子Equipment Fesource Expcutorcoimputable resourceResourceGrid services systemProcess systemFig. 1 Mapping of the service composition system onto the process system中国煤化工MHCNM HGMeng Qian, et al: Coordination theoretic approach to modelling grid service composition process715(b) The service relations in the service composition pro-Atomic Activity: a special one, representing a basic,cess are regarded as dependencies.indivisible, non-subdividable, atomic organizational be-(c) The living examples of simple services are viewedhaviour, as well as an instance of a basic service operationas activities. .with the following features: Acts= 0 andSa = 8.(d) The information transmitted in operation inter-Definition 5 Dependencies. They reveal the relativitydependencies in simple services are taken as messages.among the activities of the GSC, such as parts, achieve-(e) All sorts of resources and actors are viewed together ment, exception, sharing, flow and fit :as objects.Assuming dependencies as Ope Dep , there will beThey are defined as follows:OpeDep∈Acts x ActsThe factors to be considered in the grid service com-position process include objects, messages, activities andDependencies can be further classfied into the partdependencies.dependency, achievement dependency, exception depen-Definition 1 Process. The grid service compositiondency, sharing dependency, flow dependency and fit de-process is described as a tuple, defined aspendency.Peascp := (Obj, Mes, Act, OpeDep)Hasp indicates the dependencies of parts: the depen-where PeGscp stands for the grid service compositiondencies of activities and sub-activities, and the dependen-process (GSCP), Obj the objects in the GSCP, Mes thecies of activities and combined acts.in the GSCP, Act activities in the GSCP, Ope Dep the de-Achd indicates achieved by dependency: the dependen-cies among activities, among combined acts and amongpendencies in the GS activities.Definition 2 Objects. The objects in the GSCP are aactivities and combined acts are achieved by activities.Expc indicates has exception: the coordination mecha-dual tuple, denoted asnisms managing dependencies encounter exceptions.Obj:= (A,R)Shar indicates the sharing dependency: one commonwhere A (Actors) symbolizes executors, of which one typedependency between activities and services, between actsrefers to the service with people engagement, the otherand services, between activities and activities and betweensoftware substances used for automatic computation andacts and acts.processing. R denotes resources: broadly speaking, re-Flow indicates the flow dependency: the output of onesources needed in the GSCP, like contacts of sensors,activity serves as the input of another. It suggests the de-command and control systems, reconnaissance systems,pendency between activities and activities.surveillance systems, intelligence systems and arms sys-Fit indicates the fit dependency: multi-services supporttems. .one activity with the existence of between activities andDefinition 3 Message. It represents the input and out-acts and between activities (acts) and services.put of the GSCP and inside the CP.It is defined as a triple4. Visual approach to modelling thecoordination-theoretic grid serviceMes::= (Typ, Stru, Rts)composition processwhere Typ stands for the types of messages, Stru theUML is the effective tool for the process modelling [19].structures of messages, Rts relations between types andstructures.coordination-theoretic process, part of UML requires ex-Definition4 Activity. An activity may be an instancepanding to conform better with the expression of coordina-of a basic service operation or described as a triple, definedtion theory. Regarding the modelling for the coordination-astheoretic military process, the removable figure, the stateAct := (Acts, TA, Sa)figure and the communication figure of UML can be usedwhere Acts refers to the set of multiple activities, TA refersto indicate the process action, the time figure to indicate theto the time for activity: the executive period of time when sequence of activities and the constraints of time. The CO-the activity is completed, SA refers to the sequence of ac-ordination theory is mainly aimed in this paper to analyzetivitythe key services and determine the dependencies amongSA∈Acts x Actsthe activities corresp中国煤化工e with the"YHCNMH G716Journal of Systems Engineering and Electronics Vol. 21, No.4, August 2010illustration figure used to depict the activities and their de- clearly reflected in the achievements of all sorts of intel-pendencies. Table 1 shows the explanation of the examplesligence sources to be next integrated into “Conduct IPBfor expansion and the semantics of relations.(intelligence preparation of a battefield)," so as to reorga-Table 1 Example for expansion and the semantics of their relationsnize intelligence. Obviously, the two activities here implyNameSymbolExtended semantisthe existence of the fit dependency.“Exception”corresponds to the exception dependency.ActorExecutor/ ResourceFor instance, the activity managing the sharing depen-Use CaseActivitydency belongs to the coordination mechanism, thus intro-ducing new exceptions like“Resource misappropriating”,MessageMessage among activitieswith these exceptions depicted as activities, as shown inFig. 3Compositiono<>Reference relationship amongActivitiesRealizaion -. Aciee sThe dependency is managed bythe activityManage sharingManaging the exception causedExceptionby the codiation handler--h2+The flow dependency, the< < Exception> >sharing dependency and the fitDependencydependency among the__-Ft>2.activities.ResourcemisappropriatingIn order to ilustrate the activities and their dependen-cies in the coordination theory, the semantics of“Actors”Fig. 3 Exception relationsand“Use case”are expanded in part as well as the threedefined examples in the dependency mode, in one messagemode, in one exception dependency mode, in the achieve- sures to“Manage the flow dependency" is managing thement mode and in the part dependency mode.timeliness of the flow. The activity of“Manage timing”In the table,“Flow",“Sharing" and“Fit" correspond re-delivers messages by the“Initiative communication" be-spectively to the flow, the sharing and the fit dependen-tween messages and actors, as shown in Fig.4.cies, marked in turn as (a), (b) and (C) in Fig. 2. In this9figure, the output of“Assess the state of battlefield" pro-Manage timingvides the input for“Develop COAs". Between the twoactivities implies the existence of the flow dependency;Initiative communicationsensors, aircrafts, satellites and people of all kinds em-Fig. 4 Messagesployed in“Plan recon" may be used for“Recon”", there-fore implying the existence of the sharing dependencydency. The achievement dependency is primarily adoptedbetween the two activities; the results of“Recon” areto depict the relationships between dependencies and ac-tivities of managing dependencies. As shown in Fig. 5, aAssess thesharing dependency is achieved by the activity of“ManageDevelop COAs、 battle feild statesharing".(@) The flow dependency●→lacception + analysis厂+development( Mission>Plan reconRecon .analysis)OrdersCOACOAsO-productionapprovalcomparison(b) The sharing dependencyFig. 5 Achievement dependencyReconConduct IPB“Hasp”corresponds to the part dependency. For exam-ple, the activity “Assess the state of battlefield" is accom-(c) The fit dependencyplished by introducing four services:“Plan recon”,“Con-Fig. 2 Types of dependencies in the coordination modelingduct IPB" and“Mis中国煤化工ig 6. AllYHCNMH GMeng Qian, et al.: Coordination-theoretic approach to modelling grid service composition process717the other legends and signs in this paper are defined with newly introduced in order to select or develop exceptionthe semantics of UML 2.0.handlers.Step 5 Back to the Step 3, make the iterative analysis' battle feildof another act until all the acts are finished.Step 6 Determine the acts and their dependencies as< :Haspactivities and their dependencies.< HaspStep 7 Make the plan for the service composition.Plan reconReconConduct IPB)(Task analysis6. Modelling the coordination-theoretic gridservice composition processFig. 6 Composition relation among the activitiesGenerally speaking， the process of miltary decision-5. Approach to modelling the coordination-making is composed of seven services: Receipt of mission,theoretic grid service composition processMission analysis, Course of action development, Courseof action analysis, Course of action comparison, CourseThis paper proposes an iterative modelling approach likeof action approval and Orders production, as shown inFig. 8Specifically, first each key step captured is decomposedto simultaneously elaborate the key dependencies betweenMission一 TaskL . COASthe processes of activities (including acts) so as to deter-●acception + analysis Adeveloprmcntr COAsmine the flow dependency, sharing dependency and fit de-analysis Jpendency, furthermore each type of dependency is to be .OrdersCOAr COASmanaged along with the detection of exceptions to developproductionapprovalcomparisonexception handlers, finally service coordination plans areFig. 8 Plans for the grid service compositionestablished, as shown in Fig. 7.With a view of the typical features of this compositionprocess, this paper takes it as an example to depict the mod-Proces intoDefineelling of the coordination-theoretic grid service composi-Capture key|activities,activityprocess(: activiticsconstraints" into actionsto determine the dependencies between them.The first step is to elaborate the key services to developdependencythe basic modelling for the grid service composition for thetypemilitary decision-making, and then to determine the activ-Checkingities and their dependencies, as shown in Fig. 9.exceptionHere three key services are introduced such as assess-(Define serviceNo人Yessing the state of battlefield, working out operational planscompositionand determining operational plans, considering the keyplanAnotheractivity?services concerned with the process of military decision-Fig. 7 The approach to modelling the coordination-theoretie gridmaking. Both receipt of mission and Exception of missionwill trigger the grid service composition process. The firstkey service is“Assess the state of battlefield", which con-The particular steps go as follows:sists of three services:“Plan recon”, “Recon”and“Con-Step1 Analyze the key processes of the grid service. duct IPB". The staff in action (actors) has to engage notStep 2 Decompose the key processes into activities,only in“Plan Recon" but in processing the results fromactivities in turn into acts.the reconnissance that implies the existence of the shar-Step 3 Determine the constraints of the service com-ing dependency between the service“Plan Recon" and an-position, including resources needed in acts, actors, theother“Recon". This sharing dependency is explored totime desired, events, messages and other factors.create the inter-relation between the service and the re-Step 4 Identify the dependencies between those acts,sources shared. Besides, the management of the sharingsuch as the flow, sharing and fit dependencies to next selectdependency is depicted as the exceptional way of the ser-or develop the coordination mechanism for the acts, andvice. For example, the service“Resource misappropriat-then identify and detect the dependencies and exceptions ing" is the concrete中国煤化工pendencyMHCNMH G718Journal of Systems Engineering and Electronics Vol. 21, No.4, August 2010in exception conditions. The exceptions can be settled by dependency are mostly commanders, including the chiefhandling two other services emerging from the expansionstaf and other officials in charge in staffs. Up to this step,of the service“Resource misappropriating”.the service (“Assess the state of battlefield") is interactedAt the second step, identify the key dependencies in thewith the actors, displaying the dependence of services onprocess.actors (resources). As to this case that the intelligence (out-The key services captured are decomposed into activ-put) of the service “Assess the state of Battlefield" is toities with a top-down approach to further determine and be supplied to the service “Course of action development"then manage the dependencies between activities. The ex-(input), when the bandwidth of the network for transmit-ception handlers arise in the activities of managing the de-ting intelligence is lower than the standard, the resourcespendencies. Once the key services involve the activity“As“Initiative communication" can be obtained by analyzingsess the state of battlefield", with the introduction of the the flow dependency so that the services can be connectedfour services like“Plan recon",“Recon",“Conduct IPB”with equipment resources. This connection is achieved byand“Task analysis", then, that implies the existence of thecoordinating exception handlers in the model, as shown insharing dependency between“Plan recon” and“Recon”Fig. 10.and moreover the existence of the fit dependency since theAs presented in this paper, the approach to modellingresults of“Recon”are integrated into the achievements ofthe grid service composition process contributes to the“Conduct IPB". The sharing dependency between“Plananalysis, depiction and exploitation of the grid serviceRecon”and“Recon" is achieved by another activity“Man-composition. Concretely, first the emphasis can be rapidlyaging the dependency”. The actors managing the sharingput on the principal aspects of the grid service composition! Military decision<>CHasp> ><< Hasp>>>.< Flow>>Develop COAs卜--------→Order COAof battlefield< >< Sharing>:< >( Manage sharingCommander< < Exception>>Resourceisappropriating)< Extend>> << Extend> >AllowDetect globalpreemptivetaskmetricsFig. 9 Relations between key services and resources中国煤化工TYHCNM HGMeng Qian, et al: Coordination-theoretic approach to modelling grid service composition process719( Military dccisionmaking process< Hasp< < :Hasp> >Hagp>z' Assess the sta< Flow>1 DevelopK Flow>>Order COA)、 of battlefield 欢 COAs:< H:HaspHasp2> < < Achieved by> >< Sharing一Manage( Plan recon ,ReconConductTask an-tngcalysis< < Achieved by><< Achieved by>Hasp>>ProducersharingManage fittiningbility.locationComanderInitiatie comm-< < Exeption: 2 >unicationResmisappropriatingParticipatorFlowConsumervrong_< Extend:xtend > >< Extend>< Extend>>I Allow pree ( Detect global, Monitor agents for , ProvideFilter out actorsmptive taskmetricscommiting violation) l incentiveswith poor reliabilityFig. 10 Determining dependencies between services and exception handlersprocess. What's more, all the coordinative members willsuited for more coalition members would enable us to an-be able to understand each other better through the non- alyze the connectivity, timeliness, appropriateness and ex-equivocal, uniform depiction in fixed patterns centring onpansibility of the grid service composition process.the grid service coordination. Next, the identical structureof modelling makes it convenient to exchange messages,Referencesdemonstrate achievements and develop systems in the grid[1] R. A. Paul. DoD towards software services. Proc. of 10th IEEInternational Workshop on Object-Oriented Real-Time Depend-coordination process. In addition, resources and actorsare readily identified grounded on the analysis to help di-2] I. Foster, C. Kesseman, J. M. Nick, et al.The physiol-vide the duties in the flow exploitation of the man-machineogy of the grid: an open grid services architecture for dis-tributed systems integration. Globus Project, 2002. httpcombined service composition. Fourth, the service compo-://www. globus.org/research/papers/ ogsa.pdf.3] W. van der Aalst, K. van Hee. Workflow management models,time and the analysis of the events and messages employedmethods, and systems. Massachusetts: The MIT Press, 2004.in this approach. Last, exception handlers that are devel-MathematicsofOnerations Research2003.2801 127-140oped bring the advantage to compare and select the plans5] L. Francois, C. Stephane, R. Claude. Coordination and collab-oration environments for production lines: a user acceptance is-for the grid service composition.sue. Proc. of the 9th Conference on European on ComputerSupported Cooperative Work, 2005: 407- 426.7. Conclusion6] K. Anand, H. Mendelson. Information organization for hori-zontal multimarket coordination. Management Science, 1997,The coordination- theoretic model of the grid service com-43(12): 1609-1627.7] X. Z. Cheng. Syntheses on literatures of supply chain coordina-position process provides a better understanding of thetion. Science & Technology Progress and Policy, 2006, 23(10):identical structure of the service composition activities and.196 -200.8] Y. S. Fan, C. Wu. Workflow modeling method based on coor-helps identify the differences of activities as well as thedination theory. Computer Integrated Manufacturing Systems,reasons for those differences. This paper is focused on the2001, 7(4): 1- 6. (in Chinese)consideration of dependencies, coordination mechanisms9] Y. S. Fan, C. Wu. Research on a workflow modeling methodto improve system flexibility. Journal of Software, 2002, 13(4):and exception handling in collaborative activities. Devel-oping a more complete model of the coordinative process [10] T W. Malone,中国煤化工theory andYHCNM HG720Journal of Systems Engineering and Electronics Vol. 21, No.4, August 2010how can it help design cooperative systems. Proc. of the ACMhis Ph.D. degree from National Universitv of .Conference on Computer-Supported Cooperative Work, 1990:357- 370.Defense and Technology in 2000 where he is[1] M. Klein, C. Dellarocas. Designing robust business processes.a professor now. His main research interestsinclude information system engineering, intelli-Organizing Business Knowledge, 2003: 423- 439.[12] M. Klein, C. Petti. A handbook based methodology for re-gent decision-making and planning system. Heis also a fellow of the Chinese Institute of Elec-designing business processes. Knowledge and Process Manage-tronics (CIE).T. w.Malone.K.Crowston.G.A. Herman. Organizing busi-E- mail: Phillipliu@ 263.netmess knowledeeMassachusetts: The MITPress. 2003.8 bust-Jing Wang was born in 1963. He is a M.A.[14] Field Manual 101-5. Staff organization and operations. Head-and a senior engineer of Intelligence Institutequarters, Department of the Army, 1997. http://www.dtic.mil/of Airforce's Equipment Academy. His maindoctrine/jel/Service. _pubs/101. 5.pdfresearch Interest IS remote sensing Image pro-[15] D. S. Alberts, R. E. Hayes. Planning: complex endeavors.CCRP Publications, 2007.nese Aeronautical Association (CA A).[16] Q. Y. Ma, X. G. Chen, H. Liu. A method for describing coordi-E-mail: klswj @ sohu.comnation problem based on coordination knowledge level. SystemsEngineering Theory & Practice, 2005, 25(7): 87-92.[17] M. Nikola. Contract based Web service composition. zur Erlan-Li Yao was born in 1965. She received hergung des akademischen Grades Doctor Ingenieur (Dr.Ing.) imPh.D. degree from National University of De-Fach Informatik, 2006[18] M. Nikola, M. Miroslaw. Current solutions for Web servicefense and Technology in 1995, where she is acomposition. IEEE Internet Computing, 2004, 8(6): 51- -59.protessor now. She has been researching on[19] L. Beate, K. Birgit. An evaluation of conceptual business pro-fellow of the Chinese Association for Artificialcess modelling languages. Proc. of the ACM Symposium onIntelligence (CAAI).Applied Computing, 2006.Email: liyao6522@ sina.comBiographiesWeiming Zhang was born in 1962. He re-ceived his Ph.D. degree from National Uni-versity of Defense and Technology in 2001,where he has been a professor since 1999.Meng Qian was born in 1968. He received hisHis main research interests include intelligentdecision and Intormation system engineering,lecturer now. His main research interests in-ligent decision-support system. He is also aclude information system engineering, knowl-edge management and knowledge engineering.E-mail: qianmeng@ nudt.edu.cnE-mail: Weinmingzhang@ nudt.edu.cn中国煤化工MHCNM HG