Mean Time To Recovery

specification (MTTR) The average time that a device will

take to recover from a non-terminal failure. Examples of such

devices range from self-resetting fuses (where the MTTR would

be very short, probably seconds), up to whole systems which

have to be replaced.

The MTTR would usually be part of a maintenance contract,

where the user would pay more for a system whose MTTR was 24

hours, than for one of, say, 7 days. This means the supplier

is guaranteeing to have the system up and running again within

24 hours (or 7 days) of being notified of the failure.

Some devices have a MTTR of zero, which means that they have

redundant components which can take over the instant the

primary one fails, see RAID for example.

See also Mean Time Between Failures.

(1998-05-01)