Annualized failure rate

From Free net encyclopedia

Template:Unreferenced Annualized failure rate, or short AFR is the reciprocal of the mean time between failure (MTBF) expressed in years and percent.

For example, a typical disk drive MTBF number may be 1,200,000 hours. One year has 8,760 hours.

<math>\frac{1,200,000 hours}{8760 hours / year}=136.9863 years </math>

then take the reciprocal of 136.9863 years

<math>\frac{1 failure}{136.9863 years}\times 100\%=0.73\%</math>

You can expect about 0.73 percent of the population of disk drives to fail in the average year.

See also

• Failure rate