orchestrating services. SOC lets developers dynamically grow application portfolios more quickly than ever before by• creating compound solutions that use internal organizational software assets, including enterprise information and legacy systems, and • combining these solutions with external components possibly residing in remote networks.The visionary promise of SOC is that it will be possible to easily assemble application components into a loosely coupled network of services that can create dynamic business processes and agile applications that span organizations and computing platforms.3 Such services will go well beyond simply exchanging information-the dominating mechanism for application integration today-to accessing, programming, and integrating application services encapsulated within old and new applications.Key to realizing this vision is the service-oriented architecture. SOA is a logical way of designing a software system to provide services either to end-user Service-oriented computing promotes the idea of assembling application components into a network of services that can be loosely coupled to create flexible, dynamic business processes and agile applications that span organizations and computing platforms. An SOC research road map provides a context for exploring ongoing research activities.

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Service-oriented architectures (SOA) is an emerging approach that addresses the requirements of loosely coupled, standards-based, and protocolindependent distributed computing. Typically business operations running in an SOA comprise a number of invocations of these different components, often in an event-driven or asynchronous fashion that reflects the underlying business process needs. To build an SOA a highly distributable communications and integration backbone is required. This functionality is provided by the Enterprise Service Bus (ESB) that is an integration platform that utilizes Web services standards to support a wide variety of communications patterns over multiple transport protocols and deliver value-added capabilities for SOA applications. This paper reviews technologies and approaches that unify the principles and concepts of SOA with those of event-based programing. The paper also focuses on the ESB and describes a range of functions that are designed to offer a manageable, standards-based SOA backbone that extends middleware functionality throughout by connecting heterogeneous components and systems and offers integration services. Finally, the paper proposes an approach to extend the conventional SOA to cater for essential ESB requirements that include capabilities such as service orchestration, "intelligent" routing, provisioning, integrity and security of message as well as service management. The layers in this extended SOA, in short xSOA, are used to classify research issues and current research activities.

Service-Oriented Computing (SOC) is a new computing paradigm that utilizes services as the basic constructs to support the development of rapid, low-cost and easy composition of distributed applications even in heterogeneous environments. The promise of Service-Oriented Computing is a world of cooperating services where application components are assembled with little effort into a network of services that can be loosely coupled to create flexible dynamic business processes and agile applications that may span organizations and computing platforms. The subject of Service-Oriented Computing is vast and enormously complex, spanning many concepts and technologies that find their origins in diverse disciplines that are woven together in an intricate manner. In addition, there is a need to merge technology with an understanding of business processes and organizational structures, a combination of recognizing an enterprise's pain points and the potential solutions that can be applied to correct them. The material in research spans an immense and diverse spectrum of literature, in origin and in character. As a result research activities are very fragmented. This necessitates that a broader vision and perspective be established — one that permeates and transforms the fundamental requirements of complex applications that require the use of the Service-Oriented Computing paradigm. This paper provides a Service Oriented Computing Roadmap and places on-going research activities and projects in the broader context of this roadmap. This research roadmap launches four pivotal, inherently related, research themes to Service-Oriented Computing: service foundations, service composition, service management and monitoring and service-oriented engineering.

SOA is rapidly emerging as the premier integration and architectural approach in contemporary complex, heterogeneous computing environments. SOA is not simply about deploying software: it also requires that organizations evaluate their business models, come up with service-oriented analysis and design techniques, deployment and support plans, and carefully evaluate partner/customer/supplier relationships. Since SOA is based on open standards and is frequently realized using Web services, developing meaningful Web service and business process specifications is an important requirement for SOA applications that leverage Web services. Designers and developers cannot be expected to oversee a complex service-oriented development project without relying on a sound design and development methodology. This paper provides an overview of the methods and techniques used in service-oriented design and development. Aim of this paper is to examine a service development methodology from the point of view of both service producers and requesters and review the range of elements in this methodology that are available to them.Keywords: service oriented computing; service oriented architecture; business processes; web services; design and development methodologies.Biographical notes: Michael P. Papazoglou is a professor of computer science and director of the INFOLAB at the University of Tilburg in the Netherlands. His research interests include distributed systems, service-oriented computing and Web services, enterprise application integration, and e-Business technologies and applications. He received PhD in computer systems engineering from the University of Edinburgh.Willem-Jan van den Heuvel is an associate professor of information Systems at the University of Tilburg in the Netherlands. His research interests include service-oriented computing, alignment of new enterprise system with legacy systems, and system evolution. He received a PhD in computer science from the University of Tilburg.