“…The approach we are proposing is based on the assumption that the role of the supervisor is not essential in scheduling the sub-goals but, on the contrary, a common goal can be reached by a cooperative behavior of many agents acting asynchronously [l, 2, 3, 4, 5,6,7,8,91. In this context the "global goal" does not coincide with the goals of'the individual agents but emerges from their cooperation through the completion of simple sub-goals.…”