MTTR is an acronym with several meanings, and mixing them produces nonsense comparisons. In operations it usually means recovery or repair time after a failure. In incident response it can mean time to respond. In vulnerability management it means time to remediate. Always ask which one, and from when to when.
The common expansions
- Mean time to recover or restore. How long service takes to come back after a failure.
- Mean time to repair. Often used for the hands on fixing part of an outage.
- Mean time to respond. From alert to the first containment action.
- Mean time to remediate. From a vulnerability being known to the fix being deployed.
A number labelled MTTR from a vendor, a benchmark, and your own dashboard may each measure a different one.
Why DORA moved away from it
DORA's software delivery metrics now include failed deployment recovery time, which they say replaced MTTR. It measures how long it takes to recover from a deployment that fails and needs immediate intervention. The narrower definition ties the metric to something specific and countable.
DORA also lists instability metrics, such as the share of deployments that need immediate intervention after release. These sit next to throughput, so speed is never read alone.
Why vulnerability remediation is different
Incident recovery has a clear start, the failure, and a clear end, service restored. A vulnerability has no such event. It exists quietly until someone finds it, and "fixed" can mean patched, mitigated, or no longer reachable.
That means vulnerability timing needs more rules: the start point, severity grouping, handling of reopened items, and the end point. Read SLA clock start points and why the mean misleads.
Incident response has its own pitfalls
Time to respond can be shortened by closing alerts quickly with no real investigation. Pair it with a quality sample: review a few closed alerts each month to confirm the decision was right. Time to contain is usually more meaningful than time to acknowledge.
How to name things in your reports
Avoid the bare acronym. Use full phrases in headings:
- Time to restore service (incidents).
- Time to contain (security events).
- Time to remediate, by tier (vulnerabilities).
Each should have a one line definition under the chart. Our metric definition card gives a format.
When comparing with outside benchmarks
Check the population, the clock start, whether the mean or median is used, and whether open items are included. Without those details a benchmark is a story, not a baseline.
A quick glossary you can paste
Put a short glossary on the dashboard page. For example: Time to restore service is the elapsed time from the start of customer impact to full recovery. Time to contain is the time from confirmed detection to the point where the attacker or malware can no longer spread. Time to remediate is the time from the SLA clock start to a deployed fix.
When a new report arrives with MTTR in the title, ask four questions: which expansion, which clock start, mean or median, and are open items included? Two minutes of questions can prevent a month of confusion.
Quick check
Can I still use MTTR as a term internally?
Yes, if the glossary defines it once and every chart links to it. The risk is people assuming different meanings.
Which one belongs on a security dashboard?
Time to remediate by tier for vulnerabilities, and time to contain for incidents.
Sources
Last reviewed: 19 October 2026.
