A multiply fibred automaton semantics for IWIM

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 decribed, 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. IWIM systems possess a large number of algebraic properties, a range of which are described. The relationship with other formalisations of the IWIM conception of the coordination principle is explored.