[2] Nijssen finished his study at the Eindhoven University of Technology in 1965, and started working at Philips at the department of Commercial Efficiency Research.
In 1970 he moved to the Control Data Corporation, a pioneer in the field of computer science with the European headquarters in Brussels in Belgium.
[2] During the period of 1982 to 1989 Nijssen was a full-time professor of Computer science at the University of Queensland in Brisbane, Australia, where he worked together with Terry Halpin amongst others in further developing NIAM.
[1] At Control Data early 1970s Nijssen started with fact-based modeling and developed NIAM, a fact based business practice and notation.
[3] In 1989 Nijssen and Terry Halpin published 'the book Conceptual schema and relational database design: a fact oriented approach.