A Comprehensive Course Timetabling and Student Scheduling System at the University of Waterloo

This paper describes a comprehensive course timetabling and student scheduling system that was developed for the University of Waterloo between 1979 and 1985. The system is based on a "demand-driven" philosophy where students first chose their courses, and the system tries to find the best timetable to maximize the number of satisfied requests. The problem is first decomposed into small manageable sub-problems. Each sub-problem is solved in sequence using a greedy heuristic to assign times to sections, and a Lagrangian relaxation algorithm to assign classrooms. Timetable representatives from each department have interactive access to make final modifications. Finally, each student is individually assigned to the combination of course sections that maximizes timetable satisfaction and balances section sizes. The system has been used successfully for 15 years.