FMECA or Analyzes Modes of Failure of their Effects and of their Criticality consists in identifying the possible dysfunctions of the various parts of a system and estimating the consequences. This estimation is measured by an indicator of criticality. It acts of technique of an inductive and systematic analysis of the failures of the systems, calling upon multi-field competences of a working group. The method has as a principal objective to locate the serious dysfunctions and to correct the causes of them before even as they can occur.