Quality of Service Management for Web Service Compositions

Typically, scientific applications have to be distributed across computational grid infrastructures. These applications can use existent grid services. Service components in this kind of application may have different computational platforms that should interoperate. This interoperability is supported by the Web service technology. Thus, currently, some Web service standards are used in several service-oriented grid infrastructures. The Web Services Business Process Execution Language (WS-BPEL) is an example of a standard that can be used in this context to support the definition of scientific workflows. However, its approach for building service compositions does not consider quality of service (QoS) issues. This paper proposes an approach for building service compositions according to QoS characteristics expressed using the Web services policy framework (WS-policy).