Towards parallelization of concurrent systems

A notion of parallelization of concurrent processes is proposed that satisf ies some intuitive requirements. Roughly, given a process P, a more paralle l version Q of P can be the result of replacing one of the sequential summa nds S in one of P subterms by a process R, provided that Q is functionally equivalent to P and R is either a parallel term or a summand of S. This def ines an equivalence preserving preorder on processes Q P according to which in Q parallelism is increased or the amount of redundancy is decreased. We show that our notion has some connection with the notion of factorization proposed by Milner and Moller. Finally, we identify some classes of process es for which the most parallel version is unique. (C) Elsevier, Paris.