Source: https://www.researchgate.net/profile/Christophe-Letot/publication/259639225_Reliabilitix_un_outil_d'optimisation_de_la_maintenance_base_sur_la_fiabilite/links/00b4952cff11465419000000/Reliabilitix-un-outil-doptimisation-de-la-maintenance-base-sur-la-fiabilite.pdf