During a crisis, the main goal for decision-makers consists in restoring a stabilized nominal mode. The stakeholders have to face an important pressure and drastic constraints of response time and coordination. This study proposes a method assisting these stakeholders in their choices while carrying out a performance evaluation of the activities run during the crisis response process. Currently, in crises, the performance evaluation is only used subsequently due to difficulties in gathering and aggregating information into trustable performance indicators. The interest of this paper is to present this method which permits to obtain a relevant decision support system. Decision-makers will use it to resolve the crisis based on performance assessment. A case study about crisis management within the French Red Cross non-governmental organization is developed in order to explain how performance indicators can on the one hand support crisis response management and on the other hand improve the collaboration of stakeholders.