The risks associated with processes, equipment and installations require, beyond the studies necessary to ensure the expected performances in the technical and economic fields, the taking into account, by a formal and adapted methodology, of the concerns of industrial hygiene, product quality, protection of health and safety at the workplace, prevention of major risks, protection of the environment. The project phase is a phase that corresponds to the domain of logic and rationality; an organized will, based on the scientific and technical knowledge of the moment, is at the service of an objective. Thus, the risk management approach assumes the implementation, within the plants, of a technical and procedural "base" based on a set of rules, methodologies, procedures and controls to guide the actors in their decisions and actions. However, it cannot be based solely on these elements. It also requires trained actors who respect the rules and procedures and are motivated.