Proceedings of the 37th Hawaii International Conference on System Sciences - 2004                            An Informatio...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004   Finally we present a real-world exampl...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004architecture definition, such as performa...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004                                         ...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004   bandwidth, require different kinds of ...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004source and target. At the IT level we pro...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004Agricultural unit is responsible for cont...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004application servers, but also because mes...
Proceedings of the 37th Hawaii International Conference on System Sciences - 2004[4] Maes, Rik, Daan Rijsenbrij, Onno Trui...
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An information system_architectural_framework


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An information system_architectural_framework

  1. 1. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004 An Information System Architectural Framework for Enterprise Application Integration André Vasconcelos Miguel Mira da Silva António Fernandes José Tribolet CEO - Centro de Engenharia Instituto Superior Técnico Instituto Superior Técnico CEO - Centro de Engenharia Organizacional, INESC Av. Rovisco Pais Av. Rovisco Pais Organizacional, INESC Rua Alves Redol 9 1049-001 Lisboa, Portugal 1049-001 Lisboa, Portugal Rua Alves Redol 9 1000-029 Lisboa, Portugal 1000-029 Lisboa, Portugal Abstract Although this might be true, within certain proprietary IS, the fact is that more and more organizations are Information system (IS) architectures have not paid installing a number of incompatible information systemsenough attention to integration in the past because (some are ERPs, but most are specialized for a specificintegration was not important to build ISs from scratch. task) that cannot share a single database but need to shareHowever, with the variety and number of ISs in data. So the need to integrate information systems cannotmedium/large organizations increasing, including ERP be avoided anymore, and this leads to new challenges insystems, the need for integration is bigger than ever. terms of information system architectures.Furthermore, most organizations now want to integrate In this paper we build on previous research performedtheir ISs with those belonging to other organizations. In by our research group (CEO) in this area and complementthis paper we propose an extension to our previous this research with a proposal to incorporate integrationproposals for representing IS architectures in order to aspects into an ISA.properly support a large variety of integration scenarios The paper starts with an overview of informationbetween IS, including intra and inter organizations. In system architectures and presents our own CEOparticular we support manual and automatic, framework that had already identified high-level conceptssynchronous and asynchronous integration. We also for representing integration. In particular, a concept calledpresent an example to illustrate the proposal with real “IS Service” can be used to represent integration betweenworld IS integration needs. two information system components. In our previous work however, nothing had been proposed to representKeywords: Information System Architecture, Information integration at the application or technological levels.System Integration, CEO framework, Enterprise We then present a brief introduction to the mostArchitecture, Enterprise Application Integration. important concepts in integration, in particular to show how much richer services integration can provide for than the current RPC-like synchronous services. These RPC-1. Introduction like services, for which Web Services [2] are but the latest incarnation, can be used to integrate software components, but are clearly inappropriate to integrate Integration between software components has always information systems – especially across organizations.been a fundamental part of any information system. Assuming the limitations of current ISA to representRecently, its importance has been growing due to the need integration are clear, we then propose a set of newof integrating diverse information systems, both within concepts, namely the IT Integration Block and the ITand between organizations. The move towards ERPs in Integration Service, which together can describe a varietythe last 10 years has not reduced the need for integration, of real-world integration scenarios in ISA. The “Service”but it has even increased it. And integrating diverse concept is not limited to synchronous integrationinformation systems to react online to external events is a anymore. In particular, we propose that integration shouldnecessary condition for e-business [1]. be classified according to automation level (manual or Information system architectures (ISAs) have not paid automatic) and role type (source or target). We alsosufficient importance to integration because they assume propose that integration services should be characterizedthat enforcing the existence of a single database according to their technological, synchronism, andeliminates the need for integration. organizational level. 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 1
  2. 2. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004 Finally we present a real-world example taken from a However, it should not be a definition of the softwareproject on food safety in which we participate. This used to implement the information system. Spewak alsoexample illustrates how the concepts proposed in the proposes a methodology – Enterprise Architecturepaper can be used to represent integration between Planning (EAP) – to define an application architectureinformation systems, both at the IS and IT levels. The from informational and business requirements [9].results obtained are then discussed and compared against More recently, several authors have adaptedother common approaches. Zachman’s framework and Spewak’s EAP to better address their needs, including several proposals know as2. Overview of Information System the American Federal Government [12], Joint TechnicalArchitecture Architecture [13], and the Treasury Enterprise Architecture Framework [14]. The Information System Architecture (or ISA, for 2.3. Technological Architectureshort) represents the structure of the components, theirrelationships, principles and directives [3] with the main This architecture defines the technologies that providepurpose of supporting business [4]. an environment for application building and deployment. In the 80s, a software architecture and ISA were At this level, the major technological concepts areconsidered synonymous. But in the 90s emerged the need identified, such as technologies to implementfor manipulating concepts that exceeded the description applications, inter-process communication, data storage,of how a system was internally built. The Zachman and so on [9].Framework [5] can be considered the first important At Technological Architecture level, EAB (Enterprisesignal that software architectures were not enough. IT Architecture Blueprints) is a reference landmark [15]. While software architectures represent internal system Boar confirmed that IT architectures do not have adetails (using, for example, E-R and DFD diagrams) ISA repeatable, coherent, non-ambiguous and easilyfocus on the high-level business processes [6], [7]. Using perceptible representation [15], proposing a set ofthe “city” as a metaphor, we can use the concept of “IS blueprints for defining IT architectures in a systematic,urbanization” to emphasize the need for models to guide coherent and rigorous way. However, all these proposalsthe evolution of IS independently of current technological introduce new notions and icons, not supported by anytrends [8]. rules or standards. As a result, potential users are reluctant An ISA can be divided into three levels [9]: to adopt these proposals because they are forced to Informational (or Data) Architecture – represents acquire a high-level knowledge and experience before main data types that support business; actually defining any IT architecture. Application Architecture – defines applications needed for data management and business support; 2.4. Comparison with Software Architectures Technological Architecture – represents the main In the 90’s, software architecture had similar concerns. technologies used in application implementation and In particular, there was no consensus in software the infrastructures that provide an environment for IS architecture concepts [16]. As a result, the IEEE formed a deployment. taskforce that defined a standard called “Recommended Practice for Architectural Description of Software-2.1. Informational Architecture Intensive Systems” to provide a conceptual framework for The major purpose of the Informational Architecture is software architecture [6].to identify and define the main data types that support Based on this IEEE standard, the Open Groupbusiness development [9], [10]. For example, data (the proposed the TOGAF (The Open Group Architecturalsupport of the informational architecture) can be Framework) framework for ISA design and evaluationcategorized according to different dimensions, including: [17]. This framework provides not only a methodologyprimitive vs. derived, private vs. public, and historical vs. for ISA development but also provides a taxonomy,operational vs. provisional [11]. architectural principles and standards for ISA, mostly at the technological level.2.2. Application Architecture In addition, TOGAF proposes a technical reference model that defines a taxonomy for coherent, consistent The second architecture level defines the main and hierarchical description of the services provided byapplications needed for data management and business the application platform such as data management,support [10]. This architecture defines the major network, operating system, transaction processing, andfunctional components of the architecture to guarantee system administration. Finally, TOGAF also presentsaccess to the data in acceptable time, format and cost [9]. several architecture qualities that are inherent to the 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 2
  3. 3. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004architecture definition, such as performance, availability,usability, adaptability, and portability. < CRUD process However, the TOGAF framework has severallimitations. The most import limitation is that the focus ismainly technological, not addressing either the Businessinformational or application architectures. Another servicelimitation resides in the fact that only a set of IT notions IS Serviceand principles are proposed, not concrete modelingblueprints. This makes TOGAF interesting for thinking on relatesISA from a technological viewpoint but clearlyinadequate for modeling ISA in a global and coherent Information Entity is used > IS Block has > operationway.2.5. The CEO Framework part of In order to address the issues explained above, the is implementedOrganizational Engineering Center (or CEO, for short, inPortuguese) proposed the CEO framework [18] formodeling enterprises using a restricted set of business relatesobjects. The CEO framework was defined as an UMLprofile [19] and evolved from recent research [20], [21]. exists IT Block Although the CEO framework cannot be used to definea complete ISA, it presents some interesting extensions to IT Servicerepresent dependencies between businesses and systems.The business objects defined in the framework are goals Figure 1. CEO UML Meta-model Extensions for ISA [22]for strategy modeling; processes for business processmodeling, resources for business resource modeling, and The core concepts in the CEO framework profile are:blocks for IS modeling. The CEO framework also ensures Business Process – a collection of activities thatconsistency, easy of use and provides mechanisms to produces value to a customer;maintain integrity with the ultimate goal of reducing the Information Entity – any person, place, physical thing“impedance mismatch” between business and IT or concept that is relevant in the business context andarchitectures. about which is possible and relevant (for the Recently, CEO framework founding concepts at organization) to keep information;Information System level where investigated and an UML IS Block – a collection of mechanisms and operationsprofile for ISA modeling at informational, application and organized in order to manipulate data;technological levels was proposed [22]. Figure 1 presents IT Block –infrastructure, application platform andthe current core concepts of the CEO framework (at ISA technological/software component that realizes (orlevel). implements) an (or several) IS Block(s). From a technological point of view the concepts proposed are (represented bellow in Figure 2): IT Infrastructure Block – represents the physical and infra-structural concepts: the computational nodes (servers, personal computers, mobile devices and so on) and the non-computational nodes (for example, printers, networks) that support application platforms; IT Platform Block – represents the collection of services needed for implementing and IT deploying applications. IT Application Block – represents the technological implementation of an IS Block. At this level it is relevant to consider the kind of IT Application Block (namely presentation, logic, data and coordination block), and its “technological principles” (for example, if it is implemented using components, modules, or objects), amongst other characteristics. 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 3
  4. 4. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004 belonging to other companies, and technically is quite IT Block feasible. However, in terms of IS architectures, it becomes even more fuzzy to define the borders of an IS and even the borders for an organization [23]. On the other hand, although there are many kinds of integration, it is important to note that in the end of the day all these are based on exchanging data between two ISs [24]. The differences reside on how this dataIT Infrastructure Block IT Platform Block IT Application Block exchange occurs, what kind of data is exchanged, which guarantees are offered, and so on. For example, the Figure 2. IT Block metamodel method level exchanges data between two applications while the data level exchanges data between two It is interesting to note that in [22] some integration databases. concepts are taken into account. Particular the Service Another source of confusion comes from the fact that concept is proposed as an aggregation of operations integration is both a traditional technology but has also provided by an architectural block, organized in three become very popular quite recently. In particular, Web different categories: Services promise to revolutionize both EAI and B2B even Business Service – a collection of operations though the technology behind – remote procedure call – is provided by IS Blocks that support one (or several) nothing new. In fact, XML is just a data formatting business process(es); language and solves only a small part of the integration IS Service – a set of operations provided by an IS problem. Without transactions, security, and performance, Block (to others IS Blocks); Web Services can be used to integrate applications inside IT Service – the technological services provided by an IS but are clearly not appropriate for integrating IS, application platforms (based on [17] research). and even less for B2B integration [25]. The Service is a core integration concept in ISA and Web Services discussed in a wider context become will form the basis for our proposals presented in section even more confusing, from an ISA point of view. For 4. example, SOAP [26] – a standard for exchanging XML between two applications – can be considered the most 2.6. Conclusion important part of Web Services. Not only SOAP This overview demonstrates that, currently, there is addresses a small part of the integration problem – still no mechanism to properly represent integration neglecting security, document types, quality of service, concepts in ISA at all (informational, application and workflow definition, and so on – but also there are still technological) levels in order to develop subsequent many problems to make SOAP compatible products to inspection and/or simulation of different business and work together, e.g. Java and .NET. technological scenarios. Though some recent approaches Besides that, SOAP is basically an old-fashion, (for example CEO framework) provide a starting point for synchronous, non-transactional RPC and will suffer from ISA modeling the integration concepts are not considered the problems experienced previously with DCOM and in detail. CORBA [27]. And, in our opinion, the main differences in SOAP – basically the adoption of XML and being supported by most vendors – will not be enough to 3. Information Systems Integration overcome these technological problems. Fortunately, integration is much more rich and Integration – also known as EAI, for Enterprise powerful than Web Services advocates want us to believe Application Integration – was always an important part of and offers nowadays a rich variety of dimensions that any information system. The popularity of standard ERP could and should be represented as part of an IS packages in the 90s was supposed to solve the need for architecture. Some examples of issues around integration, integration, but in fact only enlarged the problem; since in no particular order, are: the ERP cannot replace all operational IS, in particular the • Integration can occur at the data, method, interface, operational ISs that run the business, all these remaining portal, and process level – this variety basically ISs have to be integrated with the ERP. represents how the application “sees” integration, Since most organizations nowadays are more or less although all levels of course exchange data; satisfied with their IS, the main challenge became to integrate internal ISs with other external ISs. This • Integration can occur inside a computer, inside an integration between organizations – sometimes called Intranet, inside an Extranet, or on the public Internet B2B integration – just extends integration to ISs – each zone will have its own guarantees of 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 4
  5. 5. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004 bandwidth, require different kinds of security, and so The technological architecture defines which on; technologies are used to exchange data, such as XML• Integration can occur inside a department, inside an for formatting data structures, HTTP for enterprise, inside an holding, inside a value chain, or communication protocol, and digital certificates for between two (or more) unrelated enterprises – security. This is the level most computer experts are decisions can usually be imposed inside a company, familiar with, but it address only a small part of the but are more difficult inside an holding and even integration equation and is only relevant to those more difficult (or downright impossible) to impose writing software. on another company; This paper focus on the application and technological• Integration can occur inside the same country or architectures using both existing and novel concepts: between countries – for example, digital certificates The existing IS Block and IS Service concepts issued in the USA cannot be used to sign digital (proposed in [22]) can be used to represent the invoices in Europe; operations an information system depend on another.• Integration can be synchronous or asynchronous – The novel IT Integration Block (a specialization of IT asynchronous integration has no reply but has higher Block) and IT Service concepts (proposed in [22]) performance and is scalable; can be used to represent which applications exchange• Integration can be transactional – guaranteeing that data and how they exchange data. all integration steps take place (or none at all) and extending the transaction concept to the other IS; 4. Modeling Integration in ISA• Integration can offer many levels of security, from zero to non-repudiation of reception. These different The previous sections emphasized the inexistence of levels of security should be applied only when any praxis, mechanism or language for modeling necessary (in particular, between companies on the integration concepts in ISA. public Internet) since they complicate integration, This section proposes an original collection of increase costs and reduce performance; concepts (including their graphical representations) that• Integration can be used to exchange bytes (e.g. allow the semantic manipulation of integration in ISA. TCP/IP), data structures (XML), documents such as orders and invoices (EDIFACT or UBL), workflows 4.1. Integration at IS level (ebXML) or business processes – most integration The representation of a concept is critical for its projects these days are based on XML, but the real discussion and abstraction. In this paper, in compliance problems start when documents are exchanged based with the CEO framework introduced in Section 2.5, we on workflows that represent business processes; propose a set of extensions to the UML modeling• Integration can be performed directly between two (standard) language [19] in order to accommodate the ISs (e.g. peer-to-peer) or indirectly via an new integration concepts. intermediary (e.g. a message broker) – most In fact, the CEO Framework did not define properly asynchronous integration products also use an the concepts (and corresponding UML stereotypes) for intermediary to store messages, but only at the Integration modeling in ISA, although these concepts are implementation level; a broker offers more added crucial in any ISA. value services, such as converting data between two We propose that the «IS Service» concept should be different formats, defining and executing workflows, used as the core concept for modeling integration at the IS and so on. level because the IS Service already describes how the Of course, some of these issues are more important for operations, belonging to an IS Block, are aggregated andsome levels of IS architectures than other issues: made available to other IS Blocks. Although no new The informational architecture defines what kind of stereotype is proposed at the application level, the IS data types (high level, such as orders and invoices, Service is a foundation for modeling integration in ISA at not integers and strings) are exchanged between two the application level and can be easily extended later if ISs. Although these days XML seems so important, really necessary. this level is not interested whether the document is formatted according to EDIFACT or XML. 4.2. Integration IT level The application architecture defines which applications exchange data, what kind of data they The integration process can be divided into three parts exchange and how they exchange that data. For (represented bellow in Figure 3): a source (the system that example, exchange can be synchronous or calls the service or sends the message), a target and the asynchronous, manual or automatic, and so on. integration port itself representing the relation between 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 5
  6. 6. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004source and target. At the IT level we propose to split the The IT Integration Block is not further specialized tocharacteristics associated exclusively to the source, target, accommodate the large diversity of concepts and theand those associated to the relation. continuously progression in this area. However, depending on the objectives and the target audience, the Source Relation Target IT Integration Block can be specialized to model integration specific concepts such as message broker, Figure 3. Integration Process WebServices, and so on. The case study, presented in the Considering only the characteristics associated next section, exemplifies these issues.exclusively to the system (source or target), the The IT Integration Service (proposed in [22]) can beintegration can be described along two dimensions: used to model the relation port of the integration process Automation Level – the integration services executed as presented in Figure 3. We propose this component be in the source or target system are accomplished characterized in terms of: Automatically (no human interference) or Manually Technological Level –if integration takes place inside (implies human interaction); a computer, inside an Intranet, inside an Extranet, or Role Type – the system may be the source or the on the public Internet. target of data. For example, in a web service, the Synchronism Level – integration between IT Blocks source is the client; in a messaging product, the may occur synchronously (as in RPC, for example), source is the IS sending the message. or asynchronously (usually with no reply, scalable Using the IT concepts presented in Figure 2, we and with higher performance).propose that IT integration should be adopted as a novel Organizational Level – distinguishes integrationconcept to encapsulate both the platform (e.g., J2EE, .Net, between a department, inside an enterprise, inside anCORBA, etc.) and/or the IT Application. Figure 4 holding, inside a value chain, or between two (orpresents our proposed «IT Integration Block» in the scope more) unrelated organizations.of Figure 2. Figure 6 presents the proposed UML extensions in detail. IT Block «IT Integration Service» Technological Level: {Computer, Intranet, Extranet, Internet} Synchronism Level: {Asynchronous, Synchronous} Organizational Level: {Department, Enterprise, Enterprise Group, Value Chain, General Public}IT Infrastructure Block IT Platform Block IT Application Block Figure 6.IT Integration Service The next section applies all these concepts to a concrete real world example in order to validate these proposals. 5. Case Study: SafeFood IT Integration Block The main objective of the SafeFood project is to create an information system that supports retail company’s Figure 4. Proposed UML extension for modeling efforts to guarantee the quality of their food products integration concepts in ISA through the continuous exchange of (almost) real-time Figure 5 presents the attributes proposed above for the data about those products.IT Integration Block UML stereotype (in detail). The project involves not only a perishable products distribution company but also many other external « IT Integration Block » organizations, mainly suppliers. All these entities already have their own information systems that must be Automation Level: {Automatic,, Manual} integrated. For example, the Control Quality department Role Type: {Source, Target} is responsible for the products acceptance or rejection. The products storage and their distribution to the stores are performed by the Logistics Department. The Stores Figure 5. IT Integration Block in detail are responsible for selling products to the customer. The 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 6
  7. 7. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004Agricultural unit is responsible for contract management « IS Block » SafeFoodwith the Producers Organization (named ahead as OP), Systemwhich commits to delivery the perishable products on thenegotiated dates. In Figure 7 the entire ISA at the application level is « IS Block » Agricultural « IS Block » Commercial « IS Block » Procurement « IS Block »presented. The dependencies between the IS Blocks are Management System Management System Management System OP Systempresented using «IS Service». The arrows mean the implementedby implementedby implementedby implementedbydependencies between the IS Blocks. For example, the IS « IT Block» « IT Block» « IT Block» « IT Block»Block “SafeFood System” depends from the service Agricultural Commercial Procurement Management Management Management OPprovide by the IS Service “Control Quality API”. « IS Service » « IT Integration Block » « IT Integration Block » OP API Contract Information Contract Information sender Receiver « IS Block » « IS Block » Automation Level: Automatic Automation Level: Automatic Role Type: Source Role Type: Target SafeFood OP System « IT Integration Service » System Contract Information « IS Service » Technological Level: Extranet SafeFood Synchronism Level: Asynchronous API Organizational Level: Value Chain « IS Service » « IS Service » « IS Service » Figure 9. Integration between IT Blocks in detail Control Logistics API Stores API Quality API The integration between the IT Block “Commercial « IS Block » « IS Block » « IS Block » Management” and the IT Block “OP” is performed Control Quality Logistics System System Stores System through two IT Integration Blocks and an IT Integration Service. In this example, the “Contract Information” is a Figure 7. ISA at the application level data exchange between two organizations belonging to the same Value Chain. This exchange is asynchronous The dependencies between IS Blocks represent points and takes place inside an extranet (for example, a VPN onof integration between those systems. In Figure 8 the the Internet).dependencies between two concrete IS Blocks are The integration between the commercial managementrepresented in detail. IS and the procurement management is described in « IS Service » Figure 10. This integration is accomplished via a SafeFood API Contract definition intermediary system broker. The IT Integration Block « IS Block » Prices Proposal « IS Block » from the IT Block Message Broker corresponds to the Adapters usually used in the System Broker. SafeFood OP System System « IS Service » « IS Block » « IS Block » « IS Block » Comercial Procurement Message OP API Management BrokerSystem Management System System Information of the lots Is implement Is implement Is implement Crops Confirmation Prices Acceptance « IT Block» « IT Block» « IT Block» Comercial Message Procurement Management Broker ManagementFigure 8. Dependences between SafeFood System and OP « IT Integration Block » « IT Integration Block » « IT Integration Block » System Product Information sender Product Information Adapter Product Information Receiver Automation level: Automatic Automation level: Automatic Automation level: Automatic Informational Level: Source Informational Level: Source / Target Informational Level: Target The IS Block “SafeFood System” could be furtherdecomposed into three information systems (Agricultural « IT Integration Service » « IT Integration Service » Product InformationManagement System, Commercial Management System Technological level: Extranet Product Information Technological level: Extranetand Procurement Management System) as presented in Synchronism Level: Assynchronous Organizational Level: Value Chain Synchronism Level: Assynchronous Organizational Level: Value ChainFigure 9. Each of these IS Blocks are implement by an ITBlock. Figure 10. Integration using a System Broker In the example the Commercial System uses a Broker to send the products information to the Procurement System. A message broker is an integration intermediary that can be used to exchange messages between other information systems. This case study is particularly interesting not only because message brokers are positioning themselves as alternatives to both ERP and 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 7
  8. 8. Proceedings of the 37th Hawaii International Conference on System Sciences - 2004application servers, but also because message brokers Another import approach in ISA is the TOGAFplay both the role of an information system and of an framework. When comparing TOGAF and our approachintegration system. one can notice that TOGAF has a different focus – developing other issues, not addressed in our approach as6. Discussion the architecture development method (ADM), but disregarding others. Namely, TOGAF does not address The case study presented in previous section illustrates integration issues in ISA at informational or applicationpossible scenarios where our proposals for representing levels (it focus at IT level); TOGAF also does not concernintegration in the ISA are explored. Further, the case about the notation used to represent the ISA (it addressstudy exemplifies how to represent the ISA at only the concepts in a ISA).informational, application and technological levels,having integration as its main focus. 7. Conclusion The proposed extensions to the CEO Frameworkprovide the conceptual tools and visual modeling In this paper we first presented an overview ofprimitives (supported in a standard modeling language – information system architectures and then concentrated onUML) to model several integration concepts. The major their lack of support to properly represent integration. Wegap between our approach and existing research is on then proceeded with a brief introduction to the variety ofaddressing integration not only from a technological integration models that exist in the real world, trying toperspective but also from an informational and demystify the idea that all integration problems can beapplication perspectives based on an organizational solved with Web Services.framework. The main contribution of this paper is an extension to Integration is sometimes only explored from a our previous proposal for representing ISA in order tosoftware-oriented perspective. This is usual the case when include a number of integration models at both theusing a pure software development approach (as waterfall application and IT levels. In particular, we proposed that[28] or RUP [29]), where the focus is on a particular integration should have a number of characteristics (e.g.system and on its implementation, not addressing the “big manual or automatic) and not be limited to synchronouspicture” – the relation between the new system and other (from an informational, application and The paper also presented a real-world case studytechnological perspectives). These software approaches (taken from a project in which we are involved) in orderare still valid when implementing a system, however they to illustrate the proposal with concrete integrationdo not provide to the system architect the global problems between information systems.perspective for planning and discussing integration In the future we intend to explore other integrationconcepts in the global ISA (that should precede the concepts at the technological level, in particular how toimplementation of a particular software system). map the whole variety of integration technologies Other approaches have a more general aim. For currently available to a limited number of primitiveinstance, Zachman framework [5] provides the conceptual concepts. We are particularly interested in Web Servicestools for organizing and classifying the concepts that and integration across organizations where reliability andshould be addressed when planning the ISA (and latter the security are key issues.enterprise architecture). Zachman framework provides a We are also interested to develop the technologicalmore general view over the enterprise and the IS, however tools to model integration, quantify different integrationit does not propose any notation for representation of ISA scenarios in information system architecture and help theor integration concepts. Our approach, on the other hand, system architect in defining a system architecture usingintegrated in an enterprise modeling framework (CEO different integration patterns.framework) and defining the notation for integrationmodeling in ISA (based on a standard modeling language) 8. Referencesaddresses these issues. [15] proposes a set of blueprints for modeling [1] Kalakota, Ravi and Marcia Robinson, E-Business 2.0,information systems at a technological level (as presented Addison-Wesley Longman, Incorporated, section 2.3), introducing new notions and icons, not [2] W3C, World Wide Web Consortium, Web Services, 2001.supported by any tools or standards. Our approach, as, is supported on the universal modeling [3] Garlan, D. et al., Architectural Mismatch (Why It’s Hard tolanguage (a standard supported in several tools) and Build Systems Out of Existing Parts), Proceedings 17thaddresses integration not only from the technological International Conference on Software Engineering, Seatle, WA, April 23-30 1995, pp.170-185.point of view. 0-7695-2056-1/04 $17.00 (C) 2004 IEEE 8
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