International Timetabling Competition

Timetable Evaluation

A timetable's quality is reflected by two values: the number of soft constraint violations (Distance to Feasibility), and the number of soft constraint violations. In order to compare two solutions, first we will look at the Distance to Feasibility, and the solution with the lowest value for this will be the winner. If the two solutions are tied, we will then look at the number of soft constraint violations. The winner will be the solution that has the lowest value here.

The Distance to Feasibility is the total of the following numbers (all hard constraint counts as 1).

Lectures: A missing or extra lecture of a course.

Conflicts: Two conflicting lectures in the same period. Three conflicting lectures count as 3 violations: one for each pair.

RoomOccupancy: Two lectures in the same room at the same period. Any extra lecture in the same period and room counts as one more violation.

Availabilities: Each lecture in a period unavailable for that course.

After checking this, the solution will be classified based on the satisfaction of the soft constraints. The penalty to be applied each time a soft constraint is violated is the following;

RoomCapacity: For each lecture, the number of students that attend the course must be less or equal than the number of seats of all the rooms that host its lectures. Each student above the capacity counts as 1 point of penalty.

MinimumWorkingDays: The lectures of each course must be spread into a minimum number of days. Each day below the minimum counts as 5 points of penalty.

CurriculumCompactness: Lectures belonging to a curriculum should be adjacent to each other (i.e., in consecutive periods). For a given curriculum we account for a violation every time there is one lecture not adjacent to any other lecture within the same day. Each isolated lecture in a curriculum counts as 2 points of penalty.

RoomStability: All lectures of a course should be given in the same room. Each distinct room used for the lectures of a course, but the first, counts as 1 point of penalty.

We advise you to make use of the validator in order to make sure that you have understood the constraints.

Last Updated: Monday, July 30, 2007 10:46 PM