12.  Conclusion

Predictive maintenance, with its methods and technologies deployed and proven in industries 4.0 and 5.0, represents a major advance in equipment maintenance strategy in many industrial sectors.

Contrary to companies still adept at the concept popularized by the American Bert Lance in 1977, "If it ain't broke, don't fix it – ", the main aim of predictive maintenance is to estimate the residual life expectancy (RUL) of equipment in order to anticipate failures and limit their consequences (costs, safety, environmental impact, etc.). It is essential to note that RUL is a key element of predictive maintenance in industries 4.0 and 5.0. However, its implementation raises a number of challenges to ensure a positive return on investment. One of these challenges is understanding the probabilistic characteristics of failures. As Bernard Méchin points out: "The failure event...