DISCRETE EVENT SYSTEMS AND LIFE CYCLE: A PETRI NETS-BASED VIEW

The life cycle of systems that can be modelled as discrete events includes very different phases. On the other hand, their increasing complexity makes more and more important to use formal methods. Traditionally, a differrent formalism is used for each phase of the life cycle, chosen according to its "adequacy". Nonetheless, it is well known that "optimizing" each part of a system or process does not always produce a global optimum. That is something that can be applied to the sequence of phases for the design and operation of complex systems; our examples here are taken from the manufacturing domain. We will consider the idea of using only a single formal paradigm, in particular the Petri nets one. Thus, it will allow to take into account in an economic way the full work as a whole, facilitating the coherence among the different phases, as well as establishing synergies among them. That is, trying to globally optimize the life cycle.