Many studies have highlighted the fundamental role of human capital in the inventory of an organization's values, and more particularly in its positioning in relation to its competitors. For an organization, a thorough knowledge of people and their competences allows it to have good visibility of its internal resources and to build a sustainable competitive advantage. With the digital transformation of organizations and increasing complexity in business processes, actors would learn a lot and redefine continuously their working practices. Competence management has become an essential factor in industrial processes' performance. However, competences management requires a relevant system of competence identification, given its complex nature and the evolution of the company's activities. In this paper, we propose an activity trace-based system to identify and represent competences mobilized during an activity.