Key Mandatory Definitions from MIL-STD-882E
MIL-STD-882E, DoD Standard Practice for System Safety, Section 3.2, provides a set of mandatory definitions to ensure consistent terminology usage across the DoD and its contractors. Key definitions and their significance are listed here; see MIL-STD-882E, Section 3.2 for the complete set of mandatory definitions. These definitions:
- establish a common baseline for communication
- facilitate application by joint programs
- support consistent hazard tracking and risk reporting
- provide standardized terminology for communications with risk acceptance authorities
- facilitate the use of MIL-STD-882E to analyze environmental hazards
- support the risk acceptance requirements in DoDI 5000.02
- support consistency with DoDI 5000.02 and the changes to the system safety process
1. ESOH – “An acronym that refers to the combination of disciplines that encompass the processes and approaches for addressing laws, regulations, Executive Orders (E.O.), DoD policies, environmental compliance, and hazards associated with environmental impacts, system safety (e.g., platforms, systems, system-of-systems, weapons, explosives, software, ordnance, combat systems), occupational safety and health, hazardous materials management, and pollution prevention.”
Significance: Defines the scope of applicability of the 882E system safety process as required in DoDI 5000.02 for ESOH risk management.
2. Acceptable Risk – Risk that the appropriate acceptance authority (as defined in DoDI 5000.02) is willing to accept without additional mitigation.
Significance: Supports policy requirement that ESOH risks must be accepted by the acceptance authorities identified in DODI 5000.02
3. Environmental Impact – “An adverse change to the environment wholly or partially caused by the system or its use.”
Significance: Discriminates from the traditional definition of environmental impact that includes positive changes to the environment
4. Hazard – “A real or potential condition that could lead to an unplanned event or series of events (i.e. mishap) resulting in death, injury, occupational illness, damage to or loss of equipment or property, or damage to the environment.”
Significance: Includes “unplanned” to emphasize that mishaps are typically not planned events
5. Mishap – “An event or series of events resulting in unintentional death, injury, occupational illness, damage to or loss of equipment or property, or damage to the environment. For the purposes of this Standard, the term “mishap” includes negative environmental impacts from planned events.”
Significance: Includes “negative environmental impacts from planned events” to enable the environmental community to use the 882E methodology for risk assessment
6. Risk (formerly mishap risk) – “A combination of the severity of the mishap and the probability that the mishap will occur.”
Significance: Removes “mishap” for consistency with DoDI 5000.02
Note: The system safety concept of “residual risk” used in previous versions of MIL-STD-882 was intentionally excluded from MIL-STD-882E to accommodate the DoD ESOH risk acceptance policy requirements in DoDI 5000.02. The “residual risk” concept no longer applies for DoD ESOH risk acceptance. DoD changed the risk acceptance policy in March 2007 to require risk acceptance prior to any exposure of people, equipment, or the environment to a known system hazard. The residual risk concept was inconsistent with this policy requirement because the residual mishap risk concept only required risk acceptance at one point in time - after all mitigation measures had been implemented. In addition, the residual risk concept supported the “closing” of hazards, which resulted in failure to continue to seek further risk reductions throughout the system’s life-cycle.
7. Risk Level – “The characterization of risk level as High, Serious, Medium, or Low.”
Significance: Labels the High, Serious, Medium, and Low level terms for use in grouping the Risk Assessment Codes (RACs) (e.g., 1D, 3B, etc.)
8. Initial Risk – “The first assessment of the potential risk of an identified hazard. Initial risk establishes a fixed baseline for the hazard.”
Significance: Defines a common term for the initial assessment of risk
9. Event Risk – “The risk associated with a hazard as it applies to a specified hardware/software configuration during an event. Typical events include Developmental Testing/Operational Testing (DT/OT), demonstrations, fielding, post-fielding tests.”
Significance: Supports DoDI 5000.02 requirement to accept risk prior to exposing people, equipment, or the environment to known system hazards
10. Target Risk – “The projected risk level the PM plans to achieve by implementing mitigation measures consistent with the design order of precedence described in 4.3.4.”; Note: Section 4.3.4 is “Identify and document risk mitigation measures.”
Significance: Defines a common term for the anticipated risk after all planned mitigations have been implemented, verified, and validated
11. Severity – “The magnitude of potential consequences of a mishap to include: death, injury, occupational illness, damage to or loss of equipment or property, damage to the environment, or monetary loss.”
Significance: Provides a definition of severity that was not included in 882D
12. Probability – “An expression of the likelihood of occurrence of a mishap.”
Significance: Provides a definition of probability that was not included in 882D
13. Risk Assessment Code (RAC) – “A combination of one severity category and one probability level.” Note: From Section 4.
Significance: Adopts a single term to refer to the combination of severity and probability vice a Risk Assessment Value (1-20) or Hazard Risk Index
