A = MTBF / (MTBF + MTTR) - the fraction of calendar time the equipment is capable of operating.
Formula
$$ A = \frac{\text{MTBF}}{\text{MTBF} + \text{MTTR}} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $MTBF$ | Mean Time Between Failures | h | maintenance records |
| $MTTR$ | Mean Time To Repair | h | maintenance records |
| $A$ | Availability | - | result |
Sources
- IEC 60300 - Dependability management.