“…A central problem can be pointed out as follows: the accuracy of a prognostic system is related to its ability to approximate and predict the degradation of the equipment: starting from a ''current situation,'' a prognostic tool must be able to forecast the ''future possible situations.'' From the research point of view, many developments exist to support these prognostic or forecasting activities [10,16,25,50]. However, choosing an efficient technique depends on classical constraints that limit the applicability of the tools: available data-knowledge-experiences, dynamic and complexity of the system, implementation requirements (precision, computation time, etc.…”