Modelling and Prototyping Collaborative Software Processes

The correct and timely creation of systems for coordination of group work depends on the ability to express, analyze, and experiment with protocols for managing multiple work threads. We present an evolution of the Trellis model that provides a formal basis for prototyping the coordination structure of a collaboration system. Like its predecessor, the new Trellis model has the nicely exploitable duality of being both graph formalism and parallel automaton. The automaton semantics provide dynamic information about the interactions of agents in a collaboration; the graph structure forms the basis for the static link structure of a hyperdocument. We give several analysis techniques for the model, and demonstrate its use by expressing the interaction structure of some common forms of collaborative system.