the quality of being able to withstand stresses, pressures, or changes in procedure or circumstance. A system, organism or design may be said to be "robust" if it is capable of coping well with variations (sometimes unpredictable variations) in its operating environment with minimal damage, alteration or loss of functionality.
[t]he ability to withstand and recover from adverse effects on the system, subsystem, equipment, network, or service. Adverse effects may manifest themselves directly as unavailability, or indirectly as performance (delay, throughput, packet loss, session stability) degradations and the effects of security threats on inherent securityvulnerabilities. The ability of the technology, design or systems themselves to adjust capacity, reroute traffic, reconfigure, discard malicious packets and failover, for example, affects robustness to these situations.