G. M. Nijssen

In 2002 Nijssen retired as CEO at PNA Group. He remained active as member of the OMG SBVR 1.1 Revision Task Force (RTF), the OMG BPMN Revision Task Force (RTF), the OMG Architecture Ecosystem Special Interest Group (AE SIG) and the Fact Based Modeling Task Force.

Back in the Netherlands in the 1990s Nijssen developed Cognition enhanced Natural language Information Analysis Method (CogNIAM). Hereby he focused entirely on the most productive protocol for the development of business requirements and integrated business modeling.

In 1989 Nijssen and Terry Halpin published 'the book Conceptual schema and relational database design: a fact oriented approach. The introduction it declared the background of this work:

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. When returning to the Netherlands in 1989, he founded PNA Group, which stands for Professor Nijssen Associates, and accepted a position at the University of Maastricht, Netherlands.

Nijssen's research interests in the field of computer science have developed over the years. In the 1970s he was focussed on information systems and database technology.

At Control Data early 1970s Nijssen started with fact-based modeling and developed NIAM, a fact based business practice and notation. The acronym NIAM originally stood for "Nijssen's Information Analysis Methodology", and later generalised to "Natural language Information Analysis Methodology" and Binary Relationship Modeling since G. M. Nijssen was only one of many people involved in the development of the method.

Nijssen finished his study at the Eindhoven University of Technology in 1965, and started working at Philips at the department of Commercial Efficiency Research. From 1968 to 1970 he has been director of the educational institute "The Dutch Centre for Business and IT". 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. In those years he started fact-based modeling and developed NIAM. During this time, he was also associated with several academic institutions and international standards organizations. In 1974 he was co-founder of the IFIP WG 2.6 Database Experts group, where he served as its first chairman until 1983. He was also a member of IFIP WG 8.1 on Information Systems and a member of ISO TC97/SC5/WG3 working group on Conceptual Schemas.

Gerardus Maria "Sjir" Nijssen (born 18 October 1938, Schinnen) is a Dutch computer scientist, former professor of computer science at the University of Queensland, consultant, and author. Nijssen is considered the founder of verbalization in computer science, and one of the founders of business modeling and information analysis based on natural language.