Service-Oriented Architecture and Computing

Service-Oriented Computing (SOC) is a new computing paradigm that utilizes services as the primitive computing unit to support development and composition of larger-granularity services in heterogeneous environments. The specification and execution of services in such environments is meant to support agility in application structures, flexibility for business processes and development of applications that can easily span organizational boundaries. The vision is being realized with the standardization (Umapathy & Purao, 2007) of several core layers for Web Services (WS) as well as WS-* components that provide important add-ons and respond to non-functional requirements such as reliability (Erl, 2005). The overall infrastructure is being built with these components and is called Service-Oriented Architecture (SOA). Wollrath, 1999) and SOAP (Simple Object Access Protocol)/UDDI (Universal Discovery Description and Integration) (Box et al., 2000), is a relatively new term, technologies related to SOA, e.g., RPC (remote procedure call) (Birrell & Nelson, 1984), have been studied extensively since early 70s. OASIS (Organization for the Advancement of Struc-tured Information Standards) defines SOA as a collection of best practices, principles and patterns related to service-aware, enterprise-level, distributed computing. Together, SOC, WS and SOA have tremendous potential to reshape businesses, including the health and government sector (Zhao & Cheng, 2005) as well as sciences (Foster, 2005). In principle, the service-oriented approach, independent of specific programming languages or operating systems and implemented using a self-describing interface, allows organizations to expose their core competencies programmatically over the Internet or a variety of networks using standard XML-based languages and protocols (Papazoglou, Traverso, Dustdar, & Leymann, 2008). The evolving platform has spawned, over the last few years, tracks, mini-tracks as well specialized conferences such as IEEE Services Congress, International Conference on Web Services and Service-oriented Computing Conference, and has provided an impetus to considerable activity in several research communities , including computer science, software engineering, workflow and process modeling and organizational IT – broadly construed as computation-focused, software-focused and organization-focused. The computation-focused research communities are largely concerned with problems related to composition and execution. Problems of interest to this community, therefore, often include service composition in the presence of multiple services, reliability and efficient execution. The shift to SOA and WS – that includes loosely coupled services – from the product-oriented software architecture can invalidate many techniques developed for traditional software, including the software reliability models. For example, a Service-Oriented software Reliability Model (SORM) evaluates the reliability of WS in two steps, both …