Change failure rate

Change failure rate is the ratio of failed deployments to all deployments.

Summary

Change failure rate is one of the DORA metrics and a key deployment health metric in Swarmia. The exact definition of a change failure is up to you. As a rule of thumb, it should be an incident that must be remedied immediately instead of waiting until the next regular deployment. If a deployment introduces a bug that doesn't need an immediate reaction, it probably shouldn't be defined as a change failure.

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 deployment as a failure.

We look at the number of failed deployments and calculate the change failure rate by comparing this to the number of total deployments.

Example

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 Infrastructure.