Eike Best Born in 1951 in Germany, graduated in Informatik in 1974 at the Technische Hochschule Karlsruhe. He has joined projects led by Peter Lauer and Brian Randell at the University of Newcastle upon Tyne (1975-1981) where he started to cooperate with Raymond Devillers. He earned his PhD in 1982 at Newcastle and a Habilitation degree at the University of Bonn in 1988 while working at Carl Adam Petri's Institute. He has taught a range of computer science courses as a professor in Paderborn, Hildesheim, and Oldenburg (from 1996), and he has a research and project leadership record, with an emphasis on semantics and Petri nets. Raymond Devillers Born in 1945 in Belgium, graduated in Mathematics and Physics, he got a PhD Thesis in 1974 on the use of games for deadlock prevention at the University of Brussels. During a postdoctorate stay in Newcastle upon Tyne, he met Eike Best, start of a long-lasting cooperation. After a job at the Computer Center of the ULB, he started a professorial career at the same university, where he taught many different courses in practical and theoretical computer sciences. He conducted many researches, in particular about the analysis and synthesis of Petri nets, before and after his retirement in 2010.