Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts.
For a given application, survivability must be qualified by specifying the range of conditions over which the entity will survive, the minimum acceptable level or post-disturbance functionality, and the maximum acceptable downtime.
The European Survivability Workshop introduced the concept of "Mission Survivability" whilst retaining the three core areas above, either pertaining to the "survivability" of a platform through a complete mission, or the "survivability" of the mission itself (i.e. probability of mission success). Recent studies have also introduced the concept of "Force Survivability" which relates to the ability of a force rather than an individual platform to remain "mission capable".
There is no clear prioritisation of the three elements; this will depend on the characteristics and role of the platform. Some platform types, such as submarines and airplanes, minimise their susceptibility and may, to some extent, compromise in the other areas. Main Battle Tanks minimise vulnerability through the use of heavy armours. Present day surface warship designs tend to aim for a balanced combination of all three areas.
A popular term is the "survivability onion"; described as 5-8 layers:
Don't be there. If you are there, don’t be seen. If you are seen, don’t be targeted/acquired. If you are targeted/acquired, don’t be hit. If you are hit, don’t be penetrated. If you are penetrated, don’t be killed.
The classical definition of naval survivability includes three main aspects, which are susceptibility, vulnerability, and recoverability; although, recoverability is often subsumed within vulnerability.Reese, R. et al., Operationally Oriented Vulnerability Requirements in the Ship Design Process. Naval Engineers Journal, 110(1998)1, p. 19–34.
Susceptibility consists of all the factors that expose the ship to the weapons effects in a combat environment. These factors in general are the operating conditions, the threat, and the features of the ship itself. The operating conditions, such as sea state, weather and atmospheric conditions, vary considerably, and their influence is difficult to address (hence they are often not accounted for in survivability assessment). The threat is dependent on the weapons directed against the ship and weapon's performance, such as the range. The features of the ship in this sense include platform signatures (radar, infrared, acoustic, magnetic), the defensive systems on board, such as surface-to-air missiles, EW and decoys, and also the tactics employed by the platform in countering the attack (aspects such as speed, maneuverability, chosen aspect presented to the threat).
Vulnerability refers to the ability of the vessel to withstand the short-term effects of the threat weapon. Vulnerability is an attribute typical to the vessel and therefore heavily
affected by the vessel's basic characteristics such as size, subdivision, armouring, and other hardening features, and also the design of the ship's systems, in particular the location of equipment, degrees of redundancy and separation, and the presence within a system of single point failures. Recoverability refers to vessel's ability to restore and maintain its functionality after sustaining damage. Thus, recoverability is dependent on the actions aimed to neutralize the effects of the damage. These actions include firefighting, limiting the extent of flooding, and dewatering. Besides the equipment, the crew also has a vital role in recoverability.Lake, J., Warship Survivability. Conference Proceedings of International Naval Technology Expo 80, Geneve, Sveitsi 1980, p. 28–50.
The expressed goal of "crew survivability" is to ensure vehicle occupants are best protected. It goes beyond simply ensuring crew have the appropriate protective equipment and has expanded to include measuring the overpressure and blunt impact forces experienced by a vehicle from real blast incidents in order to develop medical treatment and improve overall crew survivability. Sustainable crew survivability is dependent on the effective integration of knowledge, training, and equipment.
“The capability of a system to fulfill its mission, in a timely manner, in the presence of attacks, , or .”R. J. Ellison, D. A. Fisher, R. C. Linger, H. F. Lipson, T. Longstaff, N. R. Mead, Survivable Network Systems: An Emerging Discipline, Carnegie-Mellon Software Engineering Institute Technical Report CMU/SEI-97-TR-013, 1997 revised 1999
Combat vehicle crew
Prevention and training
Network
Definitions of network survivability
See also
External links
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