A Multiply Hierarchical Automaton Semantics for the IWIM Coordination Model

The drawbacks of programming coordination activities directly within the applications software that needs them are briefly reviewed. Coordination programming helps to separate concerns, making complex coordination protocols into standalone entities; permitting separate development, verification, maintenance, and reuse. The IWIM coordination model is described, and a formal automata theoretic version of the model is developed, capturing the essentials of the framework in a fibration based approach. Specifically, families of worker automata have their communication governed by a state of a manager automaton, whose transitions correspond to reconfigurations. To capture the generality of processes in IWIM systems, the construction is generalised so that process automata can display both manager and worker traits. The relationship with other formalisations of the IWIM conception of the coordination principle is explored.