The design and implementation of an interactive course-timetabling system

We describe our design and implementation of a dual-objective course-timetabling system for the Science Division at Rollins College, and we compare the results of our system with the actual timetable that was manually constructed for the Fall 2009 school term. The course timetables at Rollins, as at most colleges in the U.S., must be created before students enroll in classes, and our “wish list” of pairs of classes that we would like to offer in non-overlapping timeslots is considerably larger than if we were to consider only those that absolutely must be in non-overlapping timeslots. This necessitates assigning different levels of conflict severity for the class pairs and setting our objective to minimize total conflict severity. Our second objective is to create timetables that result in relatively compact schedules for the instructors and students.In addition to our automatic construction, a second, equally important component of our system is a graphical user interface (GUI) that enables the user to participate in the input, construction, and modification of a timetable. In the input phase, course incompatibility, instructor and student preferences, and desire for compact schedules all require subjective judgments. The GUI allows the user to quantify and convert this information to the weighted-graph model. In the construction and modification phase, the GUI enables the user to directly assign or reassign courses to timeslots while guided by heuristics.