Blackboard-style Service Composition with Onto ⇔ SOA

We propose an approach to service composition based on the ideas from Blackboard Systems extensively investigated in AI in 1970-80s. We combine these ideas with Onto⇔SOA – a SOA design framework that relies on a restricted document-oriented and ontology-based service model to provide guidelines for construction of services. The proposed Blackboard-style composition approach requires neither extensive service model nor explicit workflow specification and enables composite functionality to emerge by bringing a number of services together and making them interact via a shared data repository. We illustrate that a Blackboard-style mechanism combined with a restricted service model is a feasible approach for non-trivial service composition scenarios. In such a scenario, described in the paper, we compose a number of services to check consistency of units of measurement in mathematical statements.