Mean Time Between Failures
Mean Time Between Faults
(MTBF, or "Mean Time Between Faults") The average time (usually expressed in hours) that a component works without failure. It is calculated by dividing the total number of failures into the total number of operating hours observed. The term can also mean the length of time a user may reasonably expect a device or system to work before an incapacitating fault occurs.
See also Mean Time To Recovery.