Systems theory to social sciences (see David Easton's seminal development of the "political system" as an analytical construct), the original theorists explored the implications of twentieth century advances in terms of systems. People have studied subjects like complexity, self-organization, connectionism and adaptive systems in the 1940s and 1950s. In fields like cybernetics, researchers such as Norbert Wiener, William Ross Ashby, John von Neumann and Heinz von Foerster, examined complex systems mathematically. John von Neumann discovered cellular automata and self-reproducing systems, again with only pencil and paper. Aleksandr Lyapunov and Jules Henri Poincaré worked on the foundations of chaos theory without any computer
Carl Adam Petri a member of the Academia Europaea. Petri's work significantly advanced the fields of parallel computing and distributed computing, and it helped define the modern studies of complex systems and workflow management systems. His contributions have been in the broader area of network theory which includes coordination models and theories of interaction, and eventually led to the formal study of software connectors. Petri was honored with the following awards: Carl Adam Petri Carl Adam Petri (12 July 1926 – 2 July 2010) was a German mathematician and computer scientist. He was born in Leipzig. Petri created his major scientific contribution, the