Leveraging Modes and UML2 for Service Brokering Specifications

A Service-Oriented Computing (SoC) architecture consists of a number of collaborating services to achieve one or more goals. Traditionally, the focus of developing services (as components) has been on the static binding of these services within a single context and constrained in an individual manner. As service architectures are designed to more dynamic, where service binding and context changes with environmental disturbance, the task of designing and analysing such architectures becomes more complex. UML2 introduces an extended notation to define component binding interfaces, enhanced activity diagrams and sequence diagrams. We propose the use of Modes to abstract a selected set of services, their coordination and reconfiguration, and use models constructed in UML2 to describe brokering requirements which can be synthesised for input to service brokers. The approach is implemented through the use of a Modes Browser, which allows service engineers to view specifications to a prototype dynamic service brokering agent.