The system safety concept calls for a risk management strategy based on identification, analysis of hazards and application of remedial controls using a systems-based approach.
[2] The concept of system safety is useful in demonstrating adequacy of technologies when difficulties are faced with probabilistic risk analysis.
A system is defined as a set or group of interacting, interrelated or interdependent elements or parts, that are organized and integrated to form a collective unity or a unified whole, to achieve a common objective.
Ineffective decision making in safety matters is regarded as the first step in the sequence of hazardous flow of events in the "Swiss cheese" model of accident causation.
Modern and more complex systems in military and NASA with computer application and controls require functional hazard analyses and a set of detailed specifications at all levels that address safety attributes to be inherent in the design.
The primary focus of any system safety plan, hazard analysis and safety assessment is to implement a comprehensive process to systematically predict or identify the operational behavior of any safety-critical failure condition or fault condition or human error that could lead to a hazard and potential mishap.
In the distant past hazards were the focus for very simple systems, but as technology and complexity advanced in the 1970s and 1980s more modern and effective methods and techniques were invented using holistic approaches.
Software intensive systems that command, control and monitor safety-critical functions require extensive software safety analyses to influence detail design requirements, especially in more autonomous or robotic systems with little or no operator intervention.
[1][2][3][4] Typically, weapons systems pertaining to ships, land vehicles, guided missiles and aircraft differ in hazards and effects; some are inherent, such as explosives, and some are created due to the specific operating environments (as in, for example, aircraft sustaining flight).
Highly complex software intensive systems with many complex interactions affecting safety-critical functions requires extensive planning, special know-how, use of analytical tools, accurate models, modern methods and proven techniques.