Table 6. <A-3-2> Recovery time metric.

Item Description
Evaluation item Defense information network(A) >> Traffic(A.3)
Metric <A-3-1> Network availability
Explanation A probability that the defense information network can be serviced without interruption
Measurement method X = MTTR
Y = X T arg e t v a l u e T arg e t v a l u e × 100 (excess ratio of recovery time)
※ MTTR (Mean Time To Repair): average time to recovery after network service outage
Data gathering method (Data sources) ■ System □ Data
□ Questionnaires □ Interview
※ Measure with network management systems (NMS)