Instructions can be found here. Basically, each exam comes with a number of students and a duration. The goal is to manage to schedule all the exams so as to minimize the number of conflicts (e.g. same student having two exams at the same time, or in a row). The interface is rather well made and will help you achieving this. Good luck ! Disc: the guy is a friend of mine, I hope it's ok. I found it cool enough to pass it on here. Also, the prize money can be sent overseas if need be.