The organisation of production of care is a task that requires three different levels of competence: operational, structural and learning skills. The organisational requirements (OR) of the Head Nurse (HN) are often centered on the operational level, to the detriment of the other two levels. This difficulty is due to the organisation which presents limited political, cognitive and pragmatic levels of rationality.The aim of this study was to identify the impact of a third party in relation to the organisation and its effect on the HN's OR. An educational device places HN students in the position of a third party to allow them to work on an organisational problem delegated by a HN. The research-intervention followed 17 projects over a period of one year.Intervention by a third party legitimised the problem by recognizing the difficulties in nursing and reconfiguring relations between healthcare professionals in a political dimension. The methods employed by the third party reassured the HN and completed their knowledge, placing particular focus on the importance of methodology and managerial posture. In practice, the third party supported the HN's power to act and coordinate the various members of the team. The third party contributes to the development of the HN's OR and completes certain limits of the HN's rationality. Nevertheless, difficulties still remain in the development of practices outside the medical team, limiting the extension to other services.A unit managerial support, a collective schedule and open spaces of discussion are recommended to bring structure and support to the OR.