reliability

The continued conformance of a device or system to a specification over an extended period of time.

Generally, invulnerability to potentially corrupting influences. Specifically: (a) stability in the face of component failure or partial destruction, e.g., in case of death of a U.S. president a predestined successor is assigned presidential powers; when a flat worm is cut both pieces grow the missing parts, head or tail; when a highway is repaired the other routes take over the traffic; (b) stability in the presence of noise (see communication, redundancy), e.g., reliable measurements are expected to be replicable in varying circumstances yielding the same results. In the social sciences much effort is spent to avoid measuring artefacts and observer biases all of which reduce the reliable transmission of data or facts. (Krippendorff)