Important Aspects of SOA: An Entry Point for Starters

                                 Qusay F. Hassan
    PhD Researcher...
new applications and systems to be easily              It is worth mentioning that the history of SOA
composed and recompo...
manages service states during its execution and         •   Contract: It provides both formal and
between different reques...
development methodologies is the evolution of           reusable form. This was achieved by the
Object-Oriented Programmin...
6. SOA and XML Web Services                           they both are composed of similar parts listed
Figure 3: SOA in Context of XML Web Services

                                                      •   More Reusability:...
•   Greater Interoperability: SOA came                 [28]. This can be accomplished by different
    with set of guideli...
methods as it allows meeting for business              emerged to sustain SOA in e-business
    needs in easy and fast man...
contain different aspects of SOA including               [1] W. T. Tsai, B. Xiao, R. A. Paul, and Y.
definition and types ...
[16] Microsoft:        Windows        Communication          [33] A. M. Riad, A. Hassan, Q. F. Hassan,
     Foundation,   ...
that have been published in international
magazines and journal. His research interests
include SOA, Web Services, distrib...
Upcoming SlideShare
Loading in …5

Important Aspects of SOA: An Entry Point for Starters.doc.doc


Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Important Aspects of SOA: An Entry Point for Starters.doc.doc

  1. 1. Important Aspects of SOA: An Entry Point for Starters Qusay F. Hassan PhD Researcher in Faculty of Computers and Information Systems, Mansoura University, Egypt Abstract service follows the client/server or request/response model in that it is expected to Because Service-Oriented Architecture (SOA) receive requests from clients to process them is one of the hottest topics that is currently and finally forward back the returned result gaining momentum, and the number of its sets. The complexity of operations that might adopters (both business and IT executives) is be performed by any service could vary from increasing in a tremendous manner, it is really simple and short operations such as calculating a must to enlist important aspects related to it simple formulas to very complex and long in order to allow these adopters to better running business processes. Service-based understand the role that it can play in both applications are developed as independent sets software and business markets. These aspects of loosely-coupled services offering well varies from the definition of SOA and key defined interfaces to their users. These users components of it, different forms of support can find and bind to services that they are given by elite software vendors to it, its interested in to start using them. evolution history, the relationship between it There is no question that SOA has gained a lot and web services, the future expectations of traction last few years, and many of large about its uses and benefits in different computing vendors have moved to it including organizations, the relationship between SOA Microsoft [2], IBM [4], HP [5, 6], BEA [7], and Enterprise Application Integration (EAI), Sun Microsystems [8], SAP [9, 10], Oracle and various applications that can use it to [11, 12, 13], Cisco [14], and many others. overcome limitations related to other Different kinds of support were given by these traditional methods. Moreover, challenges vendors in form of tools, languages, that face SOA in software market should be frameworks, and standards that emerged to addressed and discussed in order to be able to sustain SOA systems. For example, one of see the big picture and to look for better main factors that led Microsoft to develop solutions for them. .NET Framework with great support to XML Web Services and Windows Communication Keywords: SOA, Service, Service Elements, Foundation (WCF) was to support SOA [15, Web Services, EAI, HAS, SOA Applications, 16]. Also, some new specifications have been SOA Predicts, SOA Challenges, and SOSE. provided by committees that are comprised of the aforementioned vendors to support XML Web Services yielding its next generation 1. Introduction known as WS-*. These new specifications with no question have played a great role in Service-Oriented Architecture (SOA) maximizing the power of SOA and its inherent represents a new paradigm that reflects a leap capabilities allowing better and higher transition in both computing and software adoption of it. industries [1]. It has emerged after decades of In addition to the adoption of SOA by large using distributed computing technologies to software vendors, it has been widely utilized add a new element to software stack. by some of governmental agencies as a basic Abstractly, SOA is a computing paradigm that computing and modeling architectures utilizes services as fundamental elements for including U.S Department of Defense (DoD) developing systems [2]. A service could be [17]. considered as a “set of software operations and Due to this great support to SOA, there is a big components built in a way that allows them to expectation that almost all computing units be easily, flexibly, and dynamically integrated (both software and hardware) will be turned to cover both business and IT needs” [3]. Each into services in the next few years to allow 1
  2. 2. new applications and systems to be easily It is worth mentioning that the history of SOA composed and recomposed to meet business goes back to a concept known as software-as- and market ever-changing needs. a-service (SaaS) which has first appeared with Application Service Provider (ASP) software 2. Evolution of SOA model. Simply, ASP is a “third party entity that In the past, many organizations were deploys, hosts, and manages access to a unsatisfied with the delivery of custom packaged application and delivers software- developed software applications because of based services and solutions to customers their long development cycles, high costs, and across WAN from a central data center” [19]. inadequate output quality. Those reasons have So, this ASP is responsible for managing, led many of these organizations to buy large updating, maintaining, and supporting hosted and packaged solutions such as Maintenance applications as well as underlying Resource Planning (MRP), Enterprise infrastructures. These hosted applications are Resource planning (ERP), and Customer delivered over network on subscription or Relationship Management (CRM) systems. rental basis. However, these solutions have not been good Unfortunately, ASP model has suffered from alternatives because they have come with new several inherent limitations such as inability to problems including very high costs, difficult provide complete customizable applications implementation, integration complexities, long that resulted in a new generation of monolithic customization cycles, and limited flexibility. and tight-coupled architectures. These Certainly, two key pressures usually affect limitations have allowed the SOA paradigm to software market listed as follows [18]: emerge to offer delivery of complex business processes in form of network addressable 1. Heterogeneity: Most of enterprises today components known as services that could be have a giant mix of systems that were accessed and reused everywhere by everyone built over time using a verity of on condition that access permissions are technologies coming from different granted to requestors. This model enabled end- sources. Integrating such products was to-end integration between different systems or always a nightmare for IT executives. even organizations with the ability to construct 2. Change: The rate of change is increasing new applications and business processes on the in an aggressive manner especially after fly to meet new and unexpected business needs the emergence of globalization and e- [20]. business. This high rate of change represents one of the hardest problems 3. What is Service? that face organizations and enterprises in market. It also leads them to face fierce Basically, service is a self-contained (offers competition to stay in market. To solve different functionalities related to one business this challenge, software cycles should be or technical area/sub-area), cohesive (all shortened and information should be related functionalities are placed together), offered in a quick manner in order to be black box (consumers know nothing about its able to compete and gain high revenues. internals, and underlying technologies) According to the aforementioned pressures, software component that encapsulates a high software applications have turned over years level business/technical concept that can cover from large and complex packaged (siloed) specific area of whole system. systems such as inventory management, A service could be designed to be fine-grained finance, and personnel systems to the famous or coarse-grained. A fine-grained service can client/server model that was designed to handle small and specific functionality such as support cross-functional business processes. log service, database access service, fees Although the client/server systems were very calculation service, interest rate calculation beneficial to organizations, they were still service, etc. A coarse-grained service is more monolithic. powerful service that is usually composed of a IT executives think that SOA may enable them number of fine-grained services to handle to alleviate many of problems related to more complex and wide range of related heterogeneity, interoperability and market functionalities such as loan management ever-changing needs by allowing them to service, purchase order service, insurance leverage existing IT investments in a more claim service, etc. efficient form to be able fulfill organizations’ goals effectively. Moreover, a service might be stateful or stateless. A stateful service retains and 2
  3. 3. manages service states during its execution and • Contract: It provides both formal and between different requests, for example, a informal specifications of service. Formal service that is responsible for handling loans specifications use one or more of available must be stateful in order to keep state description languages such as IDL and information about the loan being processed for WSDL to describe information related to each bank client. Reversibly, a stateless service technical areas of service such as does not retain its states between different underlying programming language(s), invocations. The stateless service is the most middleware(s), network protocol(s), and used type of services in SOA because it allows other runtime aspects. On other hand, loose-coupling between requestors and offered informal specifications are textually services, enabling wider range of clients to use presented to provide general information these services. such as the purpose, functionality, Also, a service might be short-lived or long- constraints, usage of exposed service, and lived. The execution of transactions offered by expected response time. a short-lived service can take sub-seconds or • Interface: It provides technical seconds to finish working and return back representation of service operations that generated results, for example, getting or are available to be invoked by clients. Any updating a database record such as customer interface may contain information about information. On other hand, the execution of public operations, parameters, and return long-lived service may take minutes, hours, types. These interfaces are also known as days, or even months to reach its final state, stubs or proxy classes. for example, a loan management service may take months to grant a new loan to one of bank • Implementation: It contains actual logic of service that might be related to customers. accessing data, business logic, etc. This implementation logic could be 4. Service Constituent Elements encapsulated internally within service itself or it may be provided by other Technically, any service consists of three main external artifacts such as other programs, parts listed as follows [20]: code libraries, components, legacy systems, etc. Figure 1: Essential Service Elements 5. SOA in Context of Object- processes. Thus, service is an abstract, Oriented Programming and sophisticated, and coarse-grained processing unit that wraps sets of software components Component-based Development and objects working together in a harmonic environment to provide functions that the Service is different than other software service represents. modules in that it tends to provide and execute There is no question that one of the most technical/business functionalities and important advancements in modern software 3
  4. 4. development methodologies is the evolution of reusable form. This was achieved by the Object-Oriented Programming (OOP). This emergence of the Component-based methodology depends on objects to allow Development (CBD) model that utilizes programmers to model software problems in a components as main elements for building real-world manner by mapping software terms software systems. Component is a more to entities from our lives. Certainly, any object complex and abstract term than object, as it can have only states (properties) that describe represents a unit of composition of groups of its characteristics and distinguish it from other objects that work together to provide needed objects, and behaviors (operations) that are functionalities, allowing programmers to responsible for changing state values [21]. access them through a set of contractual Although OOP is a great way to model interfaces [22, 23]. software systems, objects suffer from a Technically, SOA adds a layer of abstraction number of limitations including being very on top of CBD in a way that allows fine-grained elements, as each object only programmers to use and combine components represents one small entity or even a part of a built with different programming languages, more complex entity. Moreover, objects are frameworks, and technologies. Also, service- tightly-coupled due to high dependency on orientation supports features such as dynamic inheritance that allows programmers to extend discovery of services, loose-coupling between one or more objects with new features. These different services, and improved level of limitations made the degree of dynamicity and reusability [24]. And that is why, services are reusability very small, as it only allows closer to the concept of business transactions programmers to instantiate defined classes and allowing service consumer to be totally define relationships between them into code at unaware of technical issues related to the design-time (before compilation-time). underlying components as long as defined Limited reusability offered by the OOP model services offer needed functionalities at has forced software execs to look for a more expected service-level agreement (SLA). Figure 2: Service in the context of Components and Objects 4
  5. 5. 6. SOA and XML Web Services they both are composed of similar parts listed as follows [20]: Although many technologies could be utilized • Service Provider: It is responsible for to implement SOA including CORBA; creating, managing, and maintaining message queuing technologies (such as JMS needed services. It is also responsible for and MSMQ); RMI; RPC; and providing all information needed to COM/DCOM/COM+, XML Web Services describe offered services. In XML Web technology is the most favorite choice for its Services, parameters passed to any web adopters due to a number of factors including: service and results returned from it are • Standards-based: XML Web Services represented as XML (extensible markup technology has emerged as a result of language) documents. cooperation between different large • Service Consumer: It is an entity that is software vendors including Microsoft, interested in a specific service. Service IBM, Sun Microsystems, Oracle, SAP, consumer is responsible for finding BEA, and many others. This has given needed services and binding to them in XML Web Services a great support in order to use them. In XML Web Services, almost all modern programming communication between service consumer languages, frameworks, and tools. and service provider is mainly performed • Dynamic: Because different tools and using SOAP (Simple Object Access programming languages could be used to Protocol) messages. construct the logic of XML Web Services, • Service Registry: It is a special type of they enable faster and more efficient databases that allows service provider to implementation for applications that publish available services with all related require high dynamicity in response to contracts and metadata information. UDDI market circumstances and business (Universal Discovery, Description, and requirements such as dynamic e-business. Integration) is the main type of registries • Modular: It is modular in nature, so, it used in the world of XML Web Services allows its adopters to encapsulate business allowing service consumers to query logic in terms of modules that could be published services either deployed and used separately by available programmatically or through some GUI requestors. screens to find those that best fit their needs. • Composable: Simple XML Web Services might be aggregated to yield more • Service Contract: It holds information complex ones. This allows complex that describes available services. When a business processes to be easily designed, service provider wants to expose one new implemented and modified. service, he must provide its contract to service registry in order to allow service • Simple: Implementing SOA using XML consumer to find it and to know all Web Services is very easy if compared information and guidelines that allow him with other distributed technologies such as to use it. WSDL (Web Service Description CORBA and COM family. Language) is the description language that • Cheap: It is a much cheaper than other is used by XML Web Services to describe technologies especially the proprietary different information (both functional and ones. non-functional) about available services Additionally, the basic models of SOA and including their URLs, ports, protocols, XML Web Services are almost identical, as operations, parameters, contact information, etc. 5
  6. 6. Figure 3: SOA in Context of XML Web Services • More Reusability: Once a service 7. SOA Benefits created, it can be reused more and more by different consumers and in various In fact, SOA is a fruitful approach that offers applications. Moreover, services might be lots of benefits and advantages to its adopters composed into other services for building and practitioners including: more complex ones that are responsible for executing sophisticated business • Loose-Coupling: Because consumers can processes. To enable reusability of a access services in runtime through set of service, it should be created at the contractual interfaces rather than static optimum granularity and coherency dependencies that are defined in code, levels. Granularity refers to size and scope then SOA allows consumers to of the service, whereas, coherency refers dynamically compose and recompose to putting related (technical and/or different services to build new business) functionalities together in one (composite) applications. In addition, service. SOA allows business execs to orchestrate • Higher Productivity: If developers available services in ways that allow them reused available services, then projects to build new business processes or even can go faster, and same development team modify existing ones in order to meet can be assigned to work on more projects, business requirements. resulting in great save in total • Location Transparency: With SOA, development costs. there is no need for consumers to know • Leveraging Legacy Components: physical paths of used services as they can Enterprises usually have lots of legacy only access them through set of public components and systems that were built URLs/IPs defined in service registries just overtime to cover different needs. like online websites. This feature totally Utilizing these components in modern exempts consumers from awareness of solution may not be easy or even possible technical complexities such as hardware, due to technical and cost constraints. operating systems, frameworks, and However, SOA could allow enterprises to communication infrastructures used to make use of these assets by wrapping host services. Moreover, it enables service them into a form that might be used by providers to change physical paths or modern solutions. offered services whenever needed without any impacts on service consumers. 6
  7. 7. • Greater Interoperability: SOA came [28]. This can be accomplished by different with set of guidelines and standards that methods including: enable different enterprises/organizations • Service-Oriented Integration (SOI): It to be integrated together at lower costs allows integration of different systems by and less efforts, and with higher means of services. SOI is different from effectiveness. traditional integration methods in that it • Higher Agility: SOA promotes high does not depend on information sharing levels of agility by making systems easier that suffers from Extract/Transform/Load to be built and modified. This agility (ETL) method which enforces each could be gained from avoiding redundant requestor to build his own logic in form of and isolated systems, and instead, creating proprietary interfaces to extract and well integrated systems that fulfill shared transform accessed data from available needs between different departments in data sources, but rather, it is based on enterprise/organization or even between exposing these information in form of different enterprises/organizations and readymade services that could be reused joint-venture (JV) companies that may over and over by different requestors in work together. various applications. In fact, SOI acts as a • Better Alignment between IT and second generation of the Enterprise Business Execs: One of common Application Integration (EAI), as it allows drawbacks of traditional software services to be shared and reused in methodologies is inefficient different systems. This software communication dialogues between phenomenon is also known as composite business execs and IT execs. This applications. Simply, composite drawback makes the creation of needed applications term refers to ability to software components a hard mission to quickly construct new systems by accomplish. On other hand, because SOA assembling/reassembling available defines both business requirements and services. software functions as services, then it • Business Process Modeling (BPM): offers a better communication dialogues Briefly, it tends to integrate processes between IT and business representatives, provided by different enterprises to allow allowing each of them to give inputs that end-to-end integration. This could be are mostly understood by each other. easily done if these processes are built in form of coherent services. Applying SOA 8. SOA Predicts concepts to build business processes in form of services allows business execs to According to the importance of SOA, many of easily orchestrate these services using market and research organizations have BPM and workflow tools without predicted that SOA will change both business extensive technical knowledge. and software market in an explosive manner. • Portal-Oriented Integration (POI): It For example, Gartner Group has announced tends to offer services that comprise logic that SOA will be used in part in more than needed by various portals, for example, 50% of business applications in 2007, and it Yahoo and MSN provide end-users with has expected that it will be used in 80% various types of information including software systems by 2010 [25]. The IDC information about weather, news, gossips, published a report numbered #27093 in which sports, etc. These varieties of information it predicted that projects that use web services are usually gathered from other would have $7.1 billion by 2006 with an organizations that act as service providers annual compound rate at 116% per year in the for wide range of consumers. Also, Web next few years [26]. The Radicati Group has Service for Remote Portlets (WSRP) an expectation that the SOA market would which is imposed by SOA and web reach $6.2 billion by 2008 with an annual services technology to allow integration compound rate of 50% [27]. from presentation-based perspectives could be utilized to display section(s) of 9. SOA and Enterprise Application remote portals into other portals in a very simple way and with almost no efforts Integration [29]. Certainly, these approaches are really good for most of e-business forms Typically, integrating different systems including both Business-to-Business together is one of the well known uses of SOA (B2B) and Business-to-Consumer (B2C) 7
  8. 8. methods as it allows meeting for business emerged to sustain SOA in e-business needs in easy and fast manner. such as BPEL4WS have allowed different organizations and enterprises to share their 10. SOA and Hardware Industries business processes with others, enabling them to have end-to-end integrations [37]. It is good mentioning that many hardware • E-Health: For the last two decades, industries have supported SOA in the designs the IT executives specialized in of their products. For example, Intel is providing healthcare systems were applying service-oriented approach to system trying to manage the costs and quality design where they treat Hardware as Services of provided systems. However, these (HAS) [30]. This concept aims to design systems have suffered from being hardware units as services in order to be able extremely decentralized and scattered. to interoperate them with any other resources. This problem has prevented them This feature could encourage other important from developing a single system that terms such as virtualization which is widely meets all their needs. Regarding to used in grid computing to enable sharing of this problem, many research projects resources such as files, computers, servers, have been made to utilize SOA in e- mainframes, supercomputers, software health field, and as a result, many components, and underlying data in a very experiments have been conducted and large scale and in heterogeneous environments many research papers have been to allow these resources to collaborate to solve published to discuss and solve these complex computation problems [31]. issues [38]. • E-Government: One of the most 11. SOA Applications important demands that should be fulfilled in e-government applications Nowadays, SOA is being widely adopted in is that they should be based on many various applications inside enterprises modern and widely accepted that serve different purposes including: standards [39]. SOA and web services could be combined together to design • Finance and Trading: Financial and and build interoperable, reliable, trading section represents one of the most dependable, and secured e- important fields that could utilize SOA to government applications. This could gain its inherent advantages. Typically, be accomplished by dividing SOA could be leveraged in different forms functionalities provided by e- in financial applications such as building, government applications to a set of enhancing, or even integrating them services including administration together through a standardized set of services, infrastructure services (such interfaces [32]. Different financial systems as security, printing, notification, could benefit from SOA capabilities such message transformation and as banking systems [33], Supply-Chain mediation), processes and sub- Management (SCM) systems [34], etc. processes services, and user interface • E-Business: Applying SOA in e-business services. These different services aims to add more dynamicity to could be composed and recomposed participating systems to be able to add, to meet different requirements remove, modify, or integrate them in a whenever needed [40]. more flexible and efficient manner [35]. Clearly, SOA could be considered as the 12. SOA Challenges next generation of integration methodologies that could be used in e- It is worth mentioning that one of the most business field, as it could enable different important challenges that face SOA is the lack organizations to share information to of knowledge about terms and aspects related allow merger and acquisition [20, 36]. to it [41]. Most of software courses offered by SOA has overcome problems related to e- software faculties are only based on traditional business field that have emerged as a methodologies such as OOP with some related result of using expensive and less topics such as Unified Modeling Language effective technologies such as proprietary (UML), Object-Oriented Analysis and Design interfaces, ETL, and Electronic Data (OOAD), and Object-Oriented Languages. To Interchange (EDI). Also, new standards solve this problem, curriculums offered by and technologies that have recently software faculties should be extended to 8
  9. 9. contain different aspects of SOA including [1] W. T. Tsai, B. Xiao, R. A. Paul, and Y. definition and types of services, approaches Chen, “Consumer-Centric Service-Oriented and strategies, enabler tools and technologies, Architecture: A New Approach”, Proc. of the role that SOA can play in integrating IEEE 2006 International Workshop on Collaborative Computing, Integration, and different systems, and missing points in Assurance (WCCIA), April 2006, pp. 175-180. current SOA models. This with no doubt can [2] Microsoft: "The Future of Information play a great role in yielding a new generation Technology: Growing the Talent Critical for of software specialists that can meet new Innovation", Microsoft white paper, July 2006. market needs. 06/papers/TheFutureofInformationTechnology. 13. Service-Oriented System pdf Engineering [3] A. M. Riad, Q. F. Hassan, “Service-Oriented Architecture – A New Alternative to Traditional Integration Methods in B2B As mentioned, SOA is a new paradigm in IT Applications”, Journal of Convergence market, so, applying it in an effective and Information Technologies (JCIT), Korea, efficient manner really needs some different March 2008. software engineering techniques. Service- [4] J. Y. Chung, "Services Sciences, Management Oriented System Engineering (SOSE) is an and Engineering", IBM Report, 2005. emerging topic that comprises set of software engineering techniques needed for SOA [5] Service-Oriented Architecture Services, http:// analysis, modeling, specifications, creation, 0-0-225-121.html testing, debugging, monitoring, and governance [42]. The main focus of SOSE is [6] HP’s approach to Service-Oriented to create reliable, secure, dependable, and Architecture (SOA), trustworthy service-oriented systems, and that is why many conferences and workshops have 329749-0-0-225-121.html been held to cover these needs including IEEE International Symposium on Service-Oriented [7] SOA Resource Center, System Engineering (SOSE), International Service Availability Symposium (ISAS), CNT=index.htm&FP=/content/solutions/soa/ International Workshop on Collaborative [8] Service-Oriented Architecture (SOA), Computing, Integration, and Assurance (WCCIA), the International Symposium on Service-Oriented Applications, Integration and [9] Sap Services: Enterprise SOA Services, http:// Collaboration (SOAIC), and the International Workshop on Service-Oriented Software x Engineering (IW-SOSE). All these conferences and workshops have extensively [10] SOA Middleware, discussed main concerns related to SOA, and many papers related to this topic have been published. [11] Oracle Service-Oriented Architecture, html 14. Conclusion [12] Architect Center: SOA, In this paper we have discussed some of important aspects related to SOA varying from ex.html an introduction to its terms, benefits, and challenges to different applications that could [13] Oracle® SOA Suite, utilize it. Certainly, these points aim to clarify a/soa_best_practices_1013x_drop3.pdf the role that SOA can play in both software and business markets in the coming few years. [14] Cisco IT Department Deploys Innovative Additionally, an introduction to Service- Cisco AON Solutions, Oriented System Engineering has been given to point out its relationship with SOA in order odules/ps6438/product_promotion0900aecd80 to put its adopters on the right track. 2f5ecc.html [15] Service Oriented Architecture, 15. References us/architecture/aa948857.aspx 9
  10. 10. [16] Microsoft: Windows Communication [33] A. M. Riad, A. Hassan, Q. F. Hassan, Foundation, “Leveraging SOA in Banking Systems’ Integration”, Journal of Applied Economics communication/default.aspx Science (JAES), Romania, September 2008. [17] R. Paul, “DoD Towards Software Services”, [34] T. Zhang, S. Ying, S. Cao, X. Jia, “A Tenth IEEE International Workshop on Object- Modeling Framework for Service-Oriented oriented Real-time Dependable Systems Architecture”, Proceedings of the Sixth (WORDS 05), February 2005, pp. 3-6. International Conference on Quality Software [18] M. Endrei, J. Ang, A. Arsanjani, S. Chua, P. (QSIC'06), 2006. Comte, P. Krogdahl, M. Luo, T. Newling, [35] J. Bih, “Service Oriented Architecture (SOA) “Service-Oriented Architecture and Web A New Paradigm to Implement Dynamic E- Services”, IBM Redbooks, April 2004. business Solutions”, Ubiquity -- Volume 7, [19] Y. V. Natis, M. Pezzini, R. W. Schulte, K. Issue 30, August 2006. Iijima , “Predicts 2007: SOA Advances”, 17 [36] R. Anantharangachar, K.Krishna, G. N. November 2006, Shrinivas, “Flexible Framework for Tools Integration using Service Oriented rticle4/article4.html Architecture”, IEEE International Conference [20] M. P. Papazoglou, “Service-Oriented on Services Computing (SCC'06), 2006. Computing: Concepts, Characteristics and [37] J. Pasley, “How BPEL and SOA Are Directions”. Proceeding of the Fourth Changing Web Services Development”, IEEE International Conference on Web Information Internet Computing, June, 2005. Systems Engineering (WISE'03). 2003. [38] W. M. Omar and A. T. Bendiab, “E-Health [21] G. Booch, “Object Oriented Design with Support Services Based on Service-Oriented Applications”. Benjamin-Cummings Architecture”, IEEE Computer Society, April Publishing, 1990. 2006. [22] C. Szyperski, “Component Software: Beyond [39] German Federal Ministry of Interior, “SAGA - Object-Oriented Programming”. Addison- Standards and Architectures for e-government Wesley, 2003. Applications, version 2.0”, December 2003] [23] The CBDI Forum, [OSCI “Online Services Computer Interface”, [24] S. Güner, “Architectural Approaches, Concepts and Methodologies of Service [40] B. Meneklis, A. Kaliontzoglou, C. Douligeris Oriented Architecture”, Master Thesis, D. Polemi, “Engineering and Technology Software System Institute Technical University Aspects of an e-Government Architecture Hamburg Harburg, Germany. August 2005. Based on Web Services”, Proceedings of the [25] Third European Conference on Web Services [26] I. Foster, ComputerWorld, “Grids’ Place in (ECOWS’05), IEEE, 2005. the Service-Oriented Architecture”, [41] A. LaPlante, “Education Key to SOA TechWorld, Nov.30, 2004. Success”, in, Nov. 21, 2005. [42] W. T. Tsai, M. Malek, Y. Chen1, F. Bastani, x.cfm?FeatureID=1029 “Perspectives on Service-Oriented Computing [27] J. Geopfert, M. Whalen, “An Evolutionary and Service-Oriented System Engineering”, View of Software as a Service”. IDC white Proceedings of the Second IEEE International paper 2002, Symposium on Service-Oriented System [28] D. S. Linthicum, “Next Generation Engineering (SOSE'06), 2006. Application Integration: From Simple Information to Web Services”, Addison 16. Biography Wisely, 2003. [29] T. Schaeck, "Web Services for Remote Qusay Fadhel Hassan is a Portlets (WSRP) Whitepaper". 22 September senior software engineer who 2002, IBM Corporation performs several tasks in [30] M. Chang, J. He, E. Castro-Leon, “Service- Oriented in the Computing Infrastructure”. mid/large systems including Proceedings of IEEE International symposium development, design, and on Service-Oriented System Engineering technical architecture. He has (SOSE'06), Shanghai. September 2006. received a B.S in Information Systems in 2003 [31] J. Joseph, C. Fellenstein, “Introduction to from Faculty of Computers and Information Grid Computing” .Prentice Hall PTR, April Systems, Mansoura University, Egypt. Also, 2004. he has a M.S degree in Software Engineering [32] Z. Duan, S. Bose, P. A. Stirpe, from Faculty of Computers and Information C.Shoniregun, “SOA Without Web Services: Systems, Mansoura University, Egypt. Qusay a Pragmatic Implementation of SOA for is now a PhD researcher in the Faculty of Financial Transactions Systems”, Proceedings Computers and Information Systems, of the IEEE International Conference on Services Computing (SCC’05), 2005. Mansoura University, Egypt. He has authored and coauthored a number of research papers 10
  11. 11. that have been published in international magazines and journal. His research interests include SOA, Web Services, distributed systems, Grid Computing, BPM, and EAI. 11