[Risk analysis of a complex sociotechnical system: Case of radiotherapy]

The increasing complexity of radiotherapy work situations (technological developments, dynamics of change, increased constraints, evolution of collective actions, of professions, of interfaces between people, of human-machine interfaces, etc.) and the limits of traditional FMEA method (Failure Mode and Effects Analysis) for analysing the risks incurred by radiotherapy patients generate difficulties in identifying how the work situations of a healthcare team can generate risky situations for patients. This observation has led us to develop a new method of risk analysis: the Work Complexity Sharing and Exploration Spaces (EPECT in French). The objective of this article is to better secure a care process (making practices more reliable, updating prescribed work, defining preventive and corrective measures, continuing reflections) based on an understanding of the complexity of radiotherapy work situations and a change in our way of thinking about risks.