Nowadays in France, building fire safety strategy performance analysis relies on a fire engineering study. This kind of study aims at calculating fire risk for several strategies and for fire scenarios judged as relevant. In order to achieve risk calculation, the French Scientific and technical Building Center (CSTB) has developed a simulation tool called SCHEMA-SI. This tool is based on object-oriented differential predicate-transition Petri nets and on Monte Carlo simulations and is built to generate a large number of fire scenarios. Obtained scenarios are hence used to evaluate fire risk related to the strategy to evaluate. The lower the fire risk is obtained, the more efficient the strategy is considered. This thesis aims at contributing to the development of a SCHEMA-SI based fire risk assessment method. This thesis starts by a definition of what this method should be. At this stage, it appears that one of the difficulties to overcome is the one of the problem definition by a group of fire safety concerned people. In order to solve this difficulty, a modeling method has been developed. This method, so-called ISI-Systema, relies on two main basements: - in on hand, on a graphic modeling language created to allow a group of people to think about the problem definition by using a systemic approach ; - on the other hand, on a SCHEMA-SI compatible Petri net - graphic model translation procedure. At last, a case study is proposed.
