Change failure rate
A key metric when making changes to systems is what percentage of changes to production (including, for example, software releases and infrastructure configuration changes) fail. In the context of Lean, this is the same as percent complete and accurate for the product delivery process, and is a key quality metric. β Accelerate: The Science of Lean Software and DevOps. IT Revolution Press
Change failure rate, or CFR, is total number of deployments in failure state during any given period over the total number of releases deployed during this period.

The CFR section in Vitals also provides the number of failures on the given period and a breakdown per team and deliverable having suffered a failure.
The Evolution graph shows a comparison between 3 main buckets:
- Previous 3 months: the CFR computed over the previous 3 months from the beginning of the selected period ; e.g selected period starts in the middle of June, then the months considered would be March, April, May.
- Previous month: the CFR computed over the last month from the beginning of the given period ; e.g selected period starts in the middle of June, then the month considered would be May.
- Last week: the CFR computed over the last week from the end of the selected period.