A recent thesis work sought to develop a new method to analyse the risks incurred by radiotherapy patients in France, in order to overcome the difficulties met when applying Failure Mode and Effects Analysis (FMEA) for complex socio-technical system. We would like to present this method in line with the Safety-II perspective. Actually, participating to the Workshop will be an opportunity to place this research in relation to other Safety-II approaches, and to discuss its strengths and weaknesses.