Element 3 “Assess and document risk” documents the severity category and probability level for a potential mishap(s) for each hazard.  Each risk is assessed using the definitions in Tables 1 and Table 2 below from MIL-STD-882E.

MIL-STD-882E “Standard Practice for System Safety” – Page 10

Severity Category
To determine the appropriate severity category as defined in Table 1 for a given hazard at a given point in time, identify the potential for death or injury, environmental impact, or monetary loss. A given hazard may have the potential to affect one or all of these three areas.

Severity Categories

Table 1: Severity Categories

Probability Level
To determine the appropriate probability level as defined in Table 2 for a given hazard at a given point in time, assess the likelihood of occurrence of a mishap. Probability level F is used to document cases where the hazard is no longer present. No amount of doctrine, training, warning, caution, or Personal Protective Equipment (PPE) can move a mishap probability to level F.
Probability Levels

Table 2: Probability Levels

Risk Assessment Code (RAC)
Assessed risks are expressed as a Risk Assessment Code (RAC) which is a combination of one severity category and one probability level. – See Risk Reporting Matrix

Risk Assessment Matrix

Table 3: Risk Assessment Matrix

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Updated: 7/29/2017

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