This research focused on the nursing staff in a university hospital. Its goal was to describe, based on an ergonomic approach, the complexity that characterizes the transfer of professional skills in work situations, in a context of transformations of the production world. It proposes to model the “transfer of professional skills” as a set of “processes of elaboration of formative interactions”, emphasizing the emergence, the sequence of events, and the dynamics of these processes. Our analyses are based on combining the observation of situations of transfer of skills, with individual and collective interviews (“reflective workshops”) focusing on the activity of transferring skills. Results show that the elaboration of formative interactions relies on three components that are strongly influenced by the context of production: combining professional skills, co-constructing a relationship between protagonists, and reconciling the activities of skills transfer and of production. Conversely, these results encourage us to consider the transferring of professional skills as revealing the constraints of the productive world in which it takes place.