A. These modifications correspond to the needs of the different natures.
Regulatory progress: Progress in relation to the specifications due to a modification of the legal texts (progress of the norm).
Corrective maintenance: Correction of certain reproducible errors reasonably. This allows providing the software programs with good quality of functioning.
Progressive maintenance : Ensemble of revisions, ameliorations. Provision of minor and major software programs, and update of the Documentation which is associated with them. These provisions include the ameliorations of the exploitation procedures, the minor developments, as well as certain analysis works and the functional progresses or technical which have to be realised in order to reply to the eventual users’ request’ and to be as close as possible to their work methods.