L'atteinte d'un haut niveau d'expertise par la mise en place de PGI (progiciels de gestion intégrés) : vers un effet de levier maximal. ERP implementation success is a priority for adopters and has been elusive for some. Over the last decade, both organizations putting in solutions and their ERP editors-integrators have learnt lessons and there has been a gradual improvement in implementation method. In this paper we focus on the implementation team as a community of practice. Treating the team as a community of practice, rather than as just a project team, has the effect of leveraging to a higher level of expertise. We also study the progression from novice to expert for the organization's key users and I.T. staff.