A logic-based formalism for pervasive workflow

In order to deal with dynamic events occurring in the system, we designed three basic operations over this ALNet: (i) search for end services that can trigger the target event, (ii) search for source nodes that have reachability to at least one of the end nodes, and (iii) select the source node that gives the best composition cost. However, with the addition of more and more services, the ALNet becomes larger and complex and then performing these three tasks might be computationally costly. In order to solve the problem, we proposed an abstraction method that improves the performance significantly and demonstrated that this can be an effective platform for realizing event handling in pervasive systems. As an evaluation of the ALNet, an experimental setup has been designed and the abstraction runtime performance has been tested over different sizes service network. We have found out that the abstraction runtime performance is improved (compared to one without the abstraction) and has shown a steady increase even with the increasing size of the ALNet network.