Mean Time To Repair
Can customers rely on your ability to remove defects quickly?
The start time in MTTR is when a problem arises for your consumers. The issues can be detected by users or by automated procedures. The measurement involves the time needed for code changes to fix the unwanted behavior and are made available in your SCM system, and the update makes it through your build system and gets deployed through your CI (Continuous Integration) pipeline to the production.
In its simplest form, we can calculate the MTTR by subtracting the time stamp of when the impediment was removed with the timestamp of when the impediment was detected and taking into account all such occurrences over a predefined time period.
The next step would be to get more granular in each of these periods. You might start following the triage time, the development time, the testing time, the build and release time to look for improvements.
Do you have dissatisfied customers just because of the inability to shorten the time from defect or service unavailability in the production to its removal/restoration? If so, talk about the process, talk about where to invest time - maybe to prevent the defects in the first place.