The development of risk project requires at first the census particularly of potential accidents list. This study is generally made during the risks Preliminary Hazard Analysis method. The collection of these potential accidents requires mainly, not only experts’ expertise of the field, but also Field Data Feedback. Up to Now, this crucial problem remains the archway key of the improvement of the system security level. Indeed, there is no explicit procedure to exploit systematically the results stemming from Field Data Feedback to elaborate out Preliminary Hazard Analysis. This article suggests a methodology allowing to exploit in a systematic way the Field Data Feedback in order to work out the Preliminary Hazard Analysis on one hand and take into account the potential accidents from the specification stage of the project on the other hand.