MTTR
Mean Time to Respond / Recover
Mittlere Zeit bis zur Reaktion bzw. Wiederherstellung
MTTR is the average time from detecting an incident to containing or resolving it; depending on context the R stands for respond, recover or remediate. Together with Mean Time to Detect (MTTD) it shows how quickly an organisation reacts to attacks. In vulnerability management it often measures the time until a patch is applied.