Studied since the 1980s in French Archival services from a technical point of view, long term digital preservation strategy became a priority a few years ago in the context of Vitam program. The French Archive Interdepartmental Service, in partnership with the Vitam program team and the Ministries of Culture (National Archives), for Europe and Foreign Affairs and of Armed Forces, commissioned a study in 2018 about “ The long-term sustainability of digital information “. This collective work offers a modeling of digital preservation processes and an analysis of the skills and profiles needed to implement these processes, not only for the three ministries but for any archival service wishing to diagnose its maturity.