topic: [[Safety]] people: #people/nancyleveson created: 2024-09-02 *System safety (safety III) is the process of identifying unsafe **states** of a system, and trying to mitigate the losses that occur by reducing the likelihood of being in those unsafe states and reducing the harms resulting when those states occur.* ##### what is it? Safety III is a way of thinking, focusing on systems. The goal is to [[create the conditions]] where safety can be likely, this means accounting for the likely known hazards by engineering the system to reduce the harm s of those hazards. >“This process of identifying hazards and then designing systems to eliminate, prevent, or minimize their impact is what safety engineering is all about.” (Leveson, 2020, p. 31) Hazards are states of likely loss, not the actual losses. ##### why does it matter? >“Hazard analysis, as described briefly above, involves identifying the scenarios describing the conditions under which the system will be unsafe. If a car is traveling at 100 mph, the brakes may be ineffective in preventing an accident when the road is wet even if they are effective at lower speeds and under different conditions.” (Leveson, 2020, p. 30) >![[CleanShot 2024-10-05 at 15.33.31.jpg]]“Safety Management “Principle”” (Leveson, 2020, p. 53) ##### This reminds me of > “safety is a system (emergent) property” (Leveson, 2020, p. 39) This reminds me of [[Thinking in Systems]], focusing on the states of the system, what risks may exist in those states, and how to mitigate the losses from those risks. This approach does not assume linearity, does not assume cause and effect. The ideas of safety III remind me of [[Antifragility]], [[black swan events]], and [[dealing with complexity]]. Safety III also reminds me of the emergent properties of teams: [[emergence]]. >“System components can operate 100% reliably and accidents may still result, usually from unsafe interactions among the system components caused by system design errors or simply by complexity that overwhelms our ability to identify and thus handle all potential unsafe component interactions.” (Leveson, 2020, p. 38) ##### What would the opposite argument be? tags: #note/idea | #on/systems | #on/safety ##### Sources: Aven, T. (2022). A risk science perspective on the discussion concerning Safety I, Safety II and Safety III. _Reliability Engineering & System Safety_, _217_, 108077. [https://doi.org/10.1016/j.ress.2021.108077](https://doi.org/10.1016/j.ress.2021.108077) Leveson, N. (2020). Safety III: A systems approach to safety and resilience. _MIT Eng. Syst. Lab_, _16_, 2021.