Emilia Villani received her PhD degree from the University of Sao Paulo, Brazil, in 2004. She is currently an Assistant Professor at Instituto Tecnologico de Aeronautica. Her area of work is Industrial Automation. Paulo Eigi Miyagi received his Dr.Eng. degree from Tokyo Institute of Technology, Japan, in 1988 and L.Doc. degree from the University of Sao Paulo, Brazil, in 1993. He is currently a Professor at Escola Politecnica, the University of Sao Paulo, Brazil. His area of work is Mechatronics Systems and Industrial Automation. Robert Valette received his PhD degree from LAAS-CNRS and Universite Paul Sabatier, Toulouse, France, 1971. "Docteur d'Etat" from LAAS-CNRS and Universite Paul Sabatier, Toulouse, France, 1976. Currently "Directeur de Recherche" (Chief senior researcher) at LAAS-CNRS and supervisor for real-time and critical embedded system training within the Doctoral School (Ecole Doctorale) EDSYS, a common organization of Universite Paul Sabatier, INSA and Ecole Superieure de l'Aeronautique et de l'Espace in Toulouse. After many years devoted to the study of Discrete Event Systems represented by Petri nets and their application to the local and supervisory control of manufacturing systems Robert Valette's interest currently focuses on critical embedded systems. This involves the formal verification of properties of discrete event systems with timeliness constraints and, when the behaviour of the physical system controlled by computer has to be taken into account, the formal verification of properties of hybrid systems.