At the University of Le Mans, in the framework of several teaching units, an evaluation process based on " belts " is proposed to the students, instead of a classical evaluation method based on a final examination. This evaluation approach is both certifying and formative, and respects the own rate of learning of each one. The modalities for the establishment and the progress of the belts show that this progressive evaluation process is secure. A comparison between a final examination process and a belt process is presented through the reactions and points of vue of the autors (all of them are teachers), of the students (collected by an opinion poll) and of the University institution (collected by interviews of university officials). An assessment carried out over two years presents the choices and strategies of the students that are evaluated by this process. The benefits of the belt process, in terms of skills validation, in the framework of two teaching units ("static of beams" and "optical") are also discussed.