The safety, security and risk engineering are systematic use of general findings, engineering knowledge and experiences for: ensuring safe object from internal hazards (risk engineering); from internal and external hazards (security engineering); and, in present, for optimising the protection of human lives, environment, property and economic affairs (safety engineering). Taking a comprehensive view, one needs to examine all potential conditions that could threaten the favourable operation of a given system in all stages of its life cycle, and identify the capabilities for overcoming them by prevention, preparedness, response and renovation. It uses tools, methods and techniques that indicate how we could lay out the problem in text; determine what we ought to solve; collect and create data sets so they might have a clear evidence to a given problem; select a method for data processing so outputs might be relevant to a given problem; and interpret the outputs in given conditions. Therefore, it uses a family of exact methods, tools and techniques; this paper presents a survey of fine exact methods and suggests their systemization.