Studied Mathematics and Computer Science at Eindhoven University of Technology
(TUE), graduated in 1974 and during four years a database researcher at TUE.
Has been project leader at the Ministry of Transport from 1978 until 1980.
Has been at the Department of Information Systems, Delft University of
Technology (TUD), since 1980, received his Ph.D. at TUD in 1991, was a
lecturer until 1985 and later on an associate professor. Lectures in
Database Systems and is leader of the Xplain database project. Produced a number
of technical papers, articles and books on semantic database technology and has
had wide experience with data modeling in various fields.