Calculate the DORA mean time to recovery metric from incident start to resolution.
Incident response time is the sum of four phases from an incident's onset to a responder actively working it: response = detection + triage + assignment + acknowledgment. This precedes and feeds into MTTR (which continues on through actual remediation) — reducing any of these upstream phases directly shortens the total time before resolution work can even begin.
MTTR = total_recovery_time / number_of_incidents
MTTR measures total time from incident start to full resolution; this calculator measures only the response phase — detection through acknowledgment — which is the portion of MTTR before active remediation work even begins. Response time is often called MTTA (mean time to acknowledge) in incident management terminology.
Proactive monitoring and alerting (rather than relying on user reports) is almost always faster — investing in better SLO-based alerting or synthetic monitoring typically cuts detection time far more than improving any later phase.
Triage determines severity and impact; assignment is the often-overlooked step of actually routing the incident to the right responder — on-call rotation gaps, unclear ownership, or paging the wrong team can add significant delay here even after triage is fast.
Reliable, low-friction paging (mobile push + escalation policies), clear on-call expectations, and practiced incident response drills all reduce the gap between an alert reaching a responder and them actually starting to engage.