Change failure rate is the ratio of failed deployments to all deployments.
Change failure rate is one of the DORA metrics, key to understanding your deployment health.
Swarmia uses deployments as the basis for change failures. Deploys that fix other deploys (e.g. a patch, hotfix, rollback, forward fix) mark the original deploy as failure.
We look at the number of such failed deployments and calculate change failure rate by comparing this to the number of total deployments.
If you completed 20 deploys in a week, but 5 of those failed, you would have a change failure rate of 25%.
Why it matters
A high change failure rate can indicate either an issue in your quality or deployment systems that needs to be improved.
How to use it
If you see an increase in your change failure rate, you might want to dig into the root cause with your team to help alleviate any issues in delivery.
Where to find it
You can find change failure rate (as well as the other DORA metrics) under Insights → Code → Deployments.