| Evaluation item | Computer systems(B) >> Server availability(B.2) |
| Metric | <B-2-1> Server availability |
| Explanation | A probability that the server can be serviced without interruption |
| Measurement method | X = MTTF / (MTTF + MTTR) |
| Y= X T a r g e t V a l u e × 100 (satisfaction ratio of availability) |
| ※ MTTF (Mean Time To Failure): average time of server service |
| ※ MTTR (Mean Time To Repair): average time to recovery after server service outage |
| Data gathering method (Data sources) | ■ System □ Data |
| □ Questionnaires □ Interview |
| ※ Measure with server management systems (SMS) |