Supervised by Wilfried Brauer, he continued studying for a postgraduate degree at Bonn and received his PhD in Mathematics in 1974.
From 1985 until 2010 he was head of the research group on theoretical foundations of computer science (Theoretische Grundlagen der Informatik, TGI) at the University of Hamburg.
[1] His early research is characterised by work on topological automata and systems,[2][3][4] decision problems[5][6][7] and structural properties of Petri nets.
[15][16][17][18][19] During a considerable period of his research career, Rüdiger Valk worked in close collaboration with Carl Adam Petri, the inventor of Petri nets, who held an honorary professorship at the University of Hamburg.
Furthermore, Valk contributed to the debate of how computers affect society,[20] how Informatics should be viewed as a scientific discipline[21] and undertook interdisciplinary research on models of sociology and the derived discipline of socionics as an intersection of sociology and informatics.