| Position | Period | Institution | Department |
| Primary: | |||
| Professor (tenured) | 08/01- | Arizona State University | Computer Science and Engineering |
| Dorothean Professor (tenured) | 07/97-08/01 | University of Vermont | Computer Science |
| Dorothean Professor (tenured) | 09/96-06/97 | University of Vermont | Computer Science and Electrical Engineering |
| Professor (tenured) | 07/89-08/98 | University of Waterloo | Combinatorics and Optimization |
| Associate Professor (tenured) | 09/87-06/89 | University of Waterloo | Combinatorics and Optimization |
| Associate Professor (tenured) | 01/84-08/87 07/86-08/98 | University of Waterloo | Computer Science |
| Associate Professor | 07/82-12/83 | University of Saskatchewan | Computational Science |
| Assistant Professor | 07/80-06/82 | University of Saskatchewan | Computational Science |
| Secondary: | |||
| Professor | 08/01-08/04 | University of Vermont | Computer Science |
| Professor | 09/96-08/01 | University of Vermont | Mathematics and Statistics |
| Visiting Scientist | 08/97 | Defence Science and Technology Organization Salisbury, Australia | Communications Division |
| Univ. Auckland Foundation Fellow | 03/96-06/96 | University of Auckland | Computer Science |
| Raybould Fellow | 07/94-08/94 | Univ. Queensland | Mathematics |
| Visiting Scientist | 03/93-04/93 | Rutgers University | Dimacs |
| Senior Research Fellow | 08/90-12/90 | Curtin University | Mathematics and Statistics |
| Professor | 09/90-08/98 | University of Waterloo | Computer Science |
| Research Professor | 04/90-03/93 | Carleton University | Computer Science |
| Senior Fellow | 09/89-12/89 | Simon Fraser University | Systems Science |
| Visiting Professor | 01/89-03/89 | Auburn University | Algebra, Combinatorics, Analysis |
| Senior Fellow | 09/87-10/87 | University of Minnesota | Mathematics and Applications |
| Associate Professor | 09/87-08/90 | University of Waterloo | Computer Science |
| Visiting Professor | 01/86-05/86 | University of Auckland | Computer Science |
| Visiting Assoc Prof | 09/85-12/85 | University of Toronto | Computer Science |
| Associate Professor | 01/84-08/87 | University of Waterloo | Combinatorics and Optimization |