B (Probable) safety risks would fall on the sample probability DoD Risk Management Guide criteria scale. Therefore, all level C (Occasional), D (Remote), and E (Improbable) safety risks do not naturally fit within the typical PM risk management paradigm. Table 4 MIL-STD-882E Example Probability Levels — Description Level Individual Item Fleet/Inventory Quantitative Frequent A Likely to occur often in the life Continuously Probability of occurrence of an item experienced. greater than or equal to 10-1. Probable B Will occur several times in the Will occur Probability of occurrence less life of an item frequently than 10-1 but greater than or equal to 10-2. Occasional C Likely to occur sometime in the Will occur several Probability of occurrence less life of an item times. than 10-2 but greater than or equal to 10-3. Remote D Unlikely, but possible to occur Unlikely but can Probability of occurrence less in the life of an item reasonably be than 10-3 but greater than or expected to occur. equal to 10-5. Improbable E So unlikely, it can be assumed Unlikely to occur, Probability of occurrence less occurrence may not be but possible. than 10-6 experienced in the life of an item Eliminated F Incapable of occurrence within the life of an item. This category is used when potential hazards are identified and later eliminated. The system safety professional typically combines the severity and probability levels in a safety risk matrix, as shown in Figure 2. SEVERITY Catastrophic Critical Marginal Negligible (1) (2) (3) (4) PROBABILITY Frequent (A) HIGH HIGH SERIOUS MEDIUM 10% ≥ Probable (B) HIGH HIGH SERIOUS MEDIUM ≥1<10% Occasional (C) HIGH SERIOUS MEDIUM LOW ≥0.1<1% Remote (D) SERIOUS MEDIUM MEDIUM LOW ≥0.0001<0.1% Improbable (E) MEDIUM MEDIUM MEDIUM LOW <0.0001 Eliminated Eliminated (F) Figure 2 Safety Risk Matrix —
B (Probable) safety risks would fall on the DoD Risk Management Guide sample probability criteria scale. Therefore, all level C (Occasional), D (Remote), and E (Improbable) safety risks do not naturally fit within the typical PM risk management paradigm. Table 4 — MIL-STD-882E Example Probability Levels Description Level Individual Item Fleet/Inventory Quantitative Frequent A Likely to occur often in the life of an item Continuously experienced. Probability of occurrence greater than or equal to 10-1. Probable B Will occur several times in the life of an item Will occur frequently Probability of occurrence less than 10-1 but greater than or equal to 10-2. Occasional C Likely to occur sometime in the life of an item Will occur several times. Probability of occurrence less than 10-2 but greater than or equal to 10-3. Remote D Unlikely, but possible to occur in the life of an item Unlikely but can reasonably be expected to occur. Probability of occurrence less than 10-3 but greater than or equal to 10-5. Improbable E So unlikely, it can be assumed occurrence may not be experienced in the life of an item Unlikely to occur, but possible. Probability of occurrence less than 10-6 Eliminated F Incapable of occurrence within the life of an item. This category is used when potential hazards are identified and later eliminated. The system safety professional typically combines the severity and probability levels in a safety risk matrix, as shown in Figure 2. SEVERITY Catastrophic (1) Critical (2) Marginal (3) Negligible (4) PROBABILITY Frequent (A) ≥ 10% HIGH HIGH SERIOUS MEDIUM Probable (B) ≥1<10% HIGH HIGH SERIOUS MEDIUM Occasional (C) ≥0.1<1% HIGH SERIOUS MEDIUM LOW Remote (D) ≥0.0001<0.1% SERIOUS MEDIUM MEDIUM LOW Improbable (E) <0.0001 MEDIUM MEDIUM MEDIUM LOW Eliminated (F) Eliminated Figure 2 — Safety Risk Matrix