Survivability
Encyclopedia
Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts.
, survivability is the quantified ability of a system
, subsystem, equipment, process, or procedure to continue to function during and after a natural or man-made disturbance; e.g. nuclear electromagnetic pulse
from the detonation of a nuclear weapon
.
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 outage duration.
after a single engagement. Survivability comprises three elements:
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, minimise their susceptibility and may to some extent compromise in the other areas. Main Battle Tanks minimise vulnerability through the use of heavy armours. Surface warship designs tend to aim for a balanced combination of all three areas.
The classical definition of naval survivability includes three main aspects which are susceptibility, vulnerability, and recoverability, although recoverability is often subsumed within vulnerability.
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, manoeuvrability, 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 feartures, and also the design of the ship's systems, in particular the location of equipments, 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 fire fighting, limiting the extent of flooding and dewatering. It shall be noted that besides the equipment also the crew has a vital role in recoverability.
s face numerous lethal hazards which are both diverse and constantly evolving. Improvised Explosive Devices
, (IEDs), mines
and enemy fire are examples of such persistent and variable threats. Historically, measures taken to mitigate these hazards were concerned with protecting the vehicle itself, but due to this achieving only limited protection the focus has now shifted to safeguarding the crew within from an ever-broadening range of threats, including
Radio Controlled IEDs (RCIEDs)
, blast, fragmentation
, heat stress
and dehydration
.
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, failure
s, or accident
s.”
Engineering
In engineeringEngineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
, survivability is the quantified ability of a system
System
System is a set of interacting or interdependent components forming an integrated whole....
, subsystem, equipment, process, or procedure to continue to function during and after a natural or man-made disturbance; e.g. nuclear electromagnetic pulse
Electromagnetic pulse
An electromagnetic pulse is a burst of electromagnetic radiation. The abrupt pulse of electromagnetic radiation usually results from certain types of high energy explosions, especially a nuclear explosion, or from a suddenly fluctuating magnetic field...
from the detonation of a nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...
.
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 outage duration.
Military survivability
In the military environment, survivability is defined as the ability to remain mission capableAvailability
In telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...
after a single engagement. Survivability comprises three elements:
- Susceptibility - the likelihood of being detected, identified, and hit
- VulnerabilityVulnerabilityVulnerability refer to the susceptibility of a person, group, society, sex or system to physical or emotional injury or attack. The term can also refer to a person who lets their guard down, leaving themselves open to censure or criticism...
- the effects of being hit by a weapon - Recoverability - longer term post hit effects, damage control and firefighting, capability restoration or (in extremis) escape and evacuation.
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, minimise their susceptibility and may to some extent compromise in the other areas. Main Battle Tanks minimise vulnerability through the use of heavy armours. Surface warship designs tend to aim for a balanced combination of all three areas.
Naval survivability
Survivability denotes the ability of a ship and its onboard systems to remain functional and continue designated mission in a man-made hostile environment. The naval vessels are designed to operate in a man made hostile environment, and therefore the survivability is a vital feature required from them. The naval vessel’s survivability is a complicated subject affecting the whole life cycle of the vessel, and should be considered from the initial design phase of every war ship.The classical definition of naval survivability includes three main aspects which are susceptibility, vulnerability, and recoverability, although recoverability is often subsumed within vulnerability.
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, manoeuvrability, 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 feartures, and also the design of the ship's systems, in particular the location of equipments, 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 fire fighting, limiting the extent of flooding and dewatering. It shall be noted that besides the equipment also the crew has a vital role in recoverability.
Combat vehicle crew survivability
The crews of military combat vehicleCombat vehicle
A combat vehicle, also known as a ground combat vehicle, is a self-propelled, weaponized military vehicle used for combat operations. Combat vehicles can be wheeled or tracked.- Automation :...
s face numerous lethal hazards which are both diverse and constantly evolving. Improvised Explosive Devices
Improvised explosive device
An improvised explosive device , also known as a roadside bomb, is a homemade bomb constructed and deployed in ways other than in conventional military action...
, (IEDs), mines
Land mine
A land mine is usually a weight-triggered explosive device which is intended to damage a target—either human or inanimate—by means of a blast and/or fragment impact....
and enemy fire are examples of such persistent and variable threats. Historically, measures taken to mitigate these hazards were concerned with protecting the vehicle itself, but due to this achieving only limited protection the focus has now shifted to safeguarding the crew within from an ever-broadening range of threats, including
Radio Controlled IEDs (RCIEDs)
Improvised explosive device
An improvised explosive device , also known as a roadside bomb, is a homemade bomb constructed and deployed in ways other than in conventional military action...
, blast, fragmentation
Fragmentation (weaponry)
Fragmentation is the process by which the casing of an artillery shell, bomb, grenade, etc. is shattered by the detonating high explosive filling. The correct technical terminology for these casing pieces is fragments , although shards or splinters can be used for non-preformed fragments...
, heat stress
Hyperthermia
Hyperthermia is an elevated body temperature due to failed thermoregulation. Hyperthermia occurs when the body produces or absorbs more heat than it can dissipate...
and dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
.
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:
Prevention and training
Threat intelligence identifying trends, emerging technologies and attack tactics used by enemy forces enables crews to implement procedures that will reduce their exposure to unnecessary risks. Such intelligence also allows for more effective pre-deployment training programs where personnel can be taught the most up-to-date developments in IED concealment for example, or undertake tailored training that will enable them to identify the likely attack strategy of enemy forces. In addition, with expert, current threat intelligence the most effective equipment can be procured or rapidly developed in support of operations.Definitions of Network Survivability
"The capability of a system to fulfill its mission, in a timely manner, in the presence of threats such as attacks or large-scale natural disasters. Survivability is a subset of resilienceResilience (network)
In computer networking: “Resilience is the ability to provide and maintain an acceptable level of service in the face of faults and challenges to normal operation.”These services include:* supporting distributed processing* supporting networked storage...
."
“The capability of a system to fulfill its mission, in a timely manner, in the presence of attacks, failure
Failure
Failure refers to the state or condition of not meeting a desirable or intended objective, and may be viewed as the opposite of success. Product failure ranges from failure to sell the product to fracture of the product, in the worst cases leading to personal injury, the province of forensic...
s, or accident
Accident
An accident or mishap is an unforeseen and unplanned event or circumstance, often with lack of intention or necessity. It implies a generally negative outcome which may have been avoided or prevented had circumstances leading up to the accident been recognized, and acted upon, prior to its...
s.”
External links
- The ResiliNets Initiative
- SURVIVE SURVIVE Vulnerability Assessment Code
- Aerospace Systems Survivability Handbook - Vol. 1 Handbook Overview
- SURMA Naval Survivability Assessment Software
- HMS Counter-Terrorist Threat Intelligence
- United States Air Force and NATO Report RTO-TR-015 AC/323/(HFM-015)/TP-1 (2001)