Survivability

Survivability is the capacity of a system, organization, or organism to withstand adverse conditions and maintain or rapidly restore essential functions. It encompasses the ability to anticipate, absorb, adapt to, and recover from disruptive events. Although related to resilience, survivability is often used to emphasize continued operation during disruption, while resilience emphasizes post-disruption recovery.

In engineering and military contexts, survivability focuses on mission continuity under stress. It relies on redundancy, fault tolerance, robust design, and rapid reconfiguration, as well as protective measures to reduce exposure to damage and to mitigate consequences. The concept guides the selection of components, architectures, and procedures that keep critical functions available despite failures or attacks.

In biological terms, survivability refers to the likelihood that an individual or population will endure a threat, such as disease or extreme conditions. It is influenced by genetics, health, behavior, and environment, and is commonly expressed as survival rates or probabilities over time.

In information technology and cyber-physical systems, survivability describes the ability to maintain essential functions in the face of cyber or physical disturbances. Strategies include defense-in-depth, diversification of components, real-time monitoring, automated fault management, and rapid recovery procedures.

On a community or organizational level, survivability involves infrastructure resilience, emergency planning, robust supply chains, and social networks that support rapid response and recovery. Across disciplines, survivability provides a framework for designing robust systems and for assessing risk, preparedness, and response capabilities.