METEOR-S: Semantic Web Services and Processes
Applying Semantics in Annotation, Quality of Service, Discovery, Composition, Execution
The growth of Web services and service oriented architecture (SOA) offers attractive basis for realizing dynamic architectures, which mirror the dynamic and ever changing business environment. With the help of industry wide acceptance of standards like Business Process Execution Language for Web Services (BPEL4WS), Web Service Description Language (WSDL) and Simple Object Access Protocol (SOAP), Web Services offer the potential of low cost and immediate integration with other applications and partners. The METEOR-S project at the LSDIS Lab, University of Georgia aims to extend these standards with Semantic Web technologies to achieve greater dynamism and scalability. Specifically, [Verma et al., 2004a; Sivashanmugam et al., 2003] focus on adding semantics to WSDL and UDDI (this work termed WSDL-S is being provided as input for next version of WSDL that will support semantic representation), [Verma et al., 2004b; Sivashanmugan et al., 2004] focus on adding semantics to BPEL4WS, and [Patil et al., 2004] discusses a semi-automatic approach for annotating Web services described using WSDL.
We endeavor to define and support the complete lifecycle of Semantic Web processes. We have identified the various stages in the lifecycle as:
Quality of Service
Workflow management systems (WfMSs) have been used to support a variety of business processes. As organizations adopt new working models, such as e-commerce, new challenges arise for workflow systems. These challenges include support for the adequate management of quality of service (QoS) and the development of new solutions to facilitate the composition of workflow applications involving Web services. The good management of QoS directly impacts the success of organizations participating in e-commerce activities by better fulfilling customer expectations and achieving customer satisfaction.
To enable adequate QoS management, research is required to develop mechanisms that specify, compute, monitor, and control the QoS of the products or services to be delivered. The composition of workflows to model e-service applications differs from the design of traditional workflows due to the number of Web services available during the composition process and to their heterogeneity. Two main problems need to be solved: how to efficiently discover Web services and how to facilitate their interoperability.
To enhance WfMSs with QoS management, we have developed a QoS model that allows for the description of nonfunctional aspects of workflow components, from a quality of service perspective. To automatically compute the overall QoS of a workflow, we have developed a mathematical model and implemented an algorithm (SWR algorithm). Our QoS model and mathematical model have been validated with the deployment and execution of a set of production workflows in the area of genetics. The analysis of the collected data proves that our models provide a suitable framework for estimating, predicting, and analyzing the QoS of production workflows.
Index words: web services, workflow management systems (WfMSs), Web Service and Web Process quality of service (QoS), Workflow Process and Web Services Composition, Ontology-driven semantic annotation of Web services, Web Service Discovery, Web Process Performance Evaluation.
Semantic Web Process = Workflow process with all components that are (Semantic) Web Services
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