This article underlines the continuous trend of social and organizational changes in firms. It intends to analyze this « movement » as a specific, long-standing process, instead of a new structure appearing in the organization. This text relies on the theoretical perspectives of the sociology of organization and the sociology of innovation, and it points out a strong development of the organizational activities of the firms, associated with a weak capacity to structure the organization on a permanent basis. It also underlines the splits in the training and the presence of « dyschronies ». Following Simmel’s analyses, it at last questions the autonomy of rules compared to action.