4.3.18.23. Survivability and Susceptibility
4.3.18.23. Survivability and Susceptibility
A system with a balanced survivability and susceptibility approach ensures operational crew and personnel safety while satisfying mission effectiveness and operational readiness requirements.
Survivability is the capability of a system and its crew to avoid or withstand a hostile environment without suffering an abortive impairment of its ability to accomplish its designated mission. Susceptibility is the degree to which a device, piece of equipment, or weapon system is open to effective attack as a result of one or more inherent weaknesses. Man-made and natural environmental conditions, described in MIL-STD-810 (sand, vibration, shock, immersion, fog, etc.), and electromagnetic environment, described in MIL-STD-461/464, also should be considered in system design.
Susceptibility is a function of operational tactics, countermeasures, probability of an enemy threat, etc. Susceptibility is considered a subset of survivability. Vulnerability is the characteristics of a system that cause it to suffer a definite degradation (loss or reduction of capability to perform the designated mission) as a result of having been subjected to a certain (defined) level of effects in an unnatural (man-made) or natural (e.g., lightning, solar storms) hostile environment. Vulnerability is also considered a subset of survivability.
Design and testing ensure that the system and crew can withstand man-made hostile environments without the crew suffering acute chronic illness, disability, or death. The Program Manager, supported by the Systems Engineer, should fully assess system and crew survivability against all anticipated threats, at all levels of conflict, throughout the system life cycle. The goal of survivability and susceptibility is to:
- Provide mission assurance while maximizing warfighter safety (or minimizing their exposure to threats)
- Incorporate balanced survivability, with consideration to the use of signature reduction with countermeasures
- Incorporate susceptibility reduction features that prevent or reduce engagement of threat weapons
- Provide mission planning and dynamic situational awareness features
The mandatory Survivability Key Performance Parameter (KPP) is applicable to all capability documents for manned systems and may be applicable to unmanned systems. The intent of the Survivability KPP includes:
- Reducing a system’s likelihood of being engaged by hostile fire, through attributes such as speed, maneuverability, detectability, and countermeasures
- Reducing the system’s vulnerability if hit by hostile fire, through attributes such as armor and redundancy of critical components
- Allowing the system to survive and continue to operate in a chemical, biological, radiological, and nuclear (CBRN) environment, if required
If the system or program has been designated by the Director, Operational Test and Evaluation (DOT&E), for live-fire test and evaluation (LFT&E) oversight, the Program Manager should integrate test and evaluation (T&E) to address crew survivability issues into the LFT&E program supporting the Secretary of Defense LFT&E Report to Congress.
If the system or program has been designated a CBRN mission-critical system, the Program Manager should address CBRN survivability, in accordance with DoDI 3150.09, The Chemical, Biological, Radiological, and Nuclear (CBRN) Survivability Policy. The Program Manager should ensure that progress toward CBRN survivability requirements is documented in the applicable Service CBRN mission-critical report.
Unless waived by the Milestone Decision Authority (MDA), mission-critical systems, including crew, regardless of acquisition category, should be survivable to the threat levels anticipated in their projected operating environment as portrayed in their platform-specific System Threat Assessment Report (STAR) (see DoDI 5000.02, Enclosures 6 and 8), or in lieu of a STAR, the appropriate capstone threat document.
The Systems Engineer should describe in the Systems Engineering Plan:
- How the design incorporates susceptibility and vulnerability reduction and CBRN survivability requirements
- How progress toward these are tracked over the acquisition life cycle
Additional techniques include rapid reconstruction (reparability) to maximize wartime availability and sortie rates and incorporating damage tolerance in the system design.
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