A systems approach provides a logical structure for problem solving which views the entire system as an integrated whole. Consequently, to ensure such a system is as safe as possible, risks must be assessed and managed in all components of this system. Civil aviation is such a system. Accordingly, it should be recognized that in such a complex and dynamic system, all threats to safety cannot be avoided and predicted; hence prevention cannot be relied on alone. It must also be recognized that system designs do not completely preclude high consequences for every threat, hence design features alone cannot be relied on. To achieve a high level of confidence, safety must be designed into and hazards eliminated or minimized.
Some basic concepts of system safety are:
Safety should be built into the system, not added on to a completed design
Safety is a property of the system, not a component
Accidents are not always caused by failures and all failures do not cause accidents
Analysis to prevent the accident is emphasized instead of reacting to the accident
Emphasis is on identifying hazards as early as possible and then designing to eliminate or control those hazards
Trade-offs and compromises are recognized in system design
This workgroup has considered these system safety concepts and incorporated key concepts into the proposed oversight system.