We consider the problem of the evaluation of the maintenance policy of a component by means of degradation modeling. We assume that the stochastic laws governing the degradation process are uncertain, and so are the related parameters. We assume that the information available is in the form of qualitative judgment by an expert. We develop a representation framework based on Possibility Theory and the concept of Fuzzy Random Variables. An example of application is given with reference to Medium-Voltage Circuit-Breaker test facility.