MTTF - Mean Time To Failure
A estimate of the average, or mean
time until a design's or component's first failure,
(you may not want to include external
failures), or disruption in the operation of the product, process,
procedure, or design occurs. Mean time until a failure assumes that the
product CAN NOT be repaired and the product CAN NOT resume any of it’s
MTTF is related to items such as expected
and/or operating life or other items that in general are not fixed or
replacement even though it sometimes may be.
In a lot of design
and components, MTTF it is especially
near to the MTBF, (Mean Time
Between Failures), which typically is a small amount longer than
MTTF. This is due to the fact that MTBF includes the repair time of the designs
or components. If a design
or component works for an extended
time, then it fails, is repaired in a reasonable amount of time, and then
once again works for an extended time, the MTTF is the average, or mean,
of the amount of time that it is in operational condition. The MTBF is the
average time between failures to include the average repair time, or MTTR.
MTTR is not the correct tool for all
applications, but is a useful measurement of reliability.
Also see MTTF
- Mean Time To Failure, Design Life, Durability,
Expected Life, Failure
Rate, and R – Reliability.