How to Improve Change Failure Rate Metric?

Software development is filled with many risks and challenges, but knowledge of the change failure rate is arguably a concept that’s not given enough attention in engineering curriculums. Change Failure Rate is one of the four metrics put forward by DORA to ensure the success of software development projects. You can check to know more about DORA metrics.

So, what really is the change failure rate?

Change failure rate refers to the probability that a change will fail in its first attempt; i.e., the percentage of changes to be reverted, lost or replaced during a given time period. This metric is important because it provides a more accurate picture of the expected change density within your project. 

Here are different ways you can improve the change failure rate.

  • Ensure all new code is covered by automated unit tests

You can start by ensuring that all new code added to your software is covered by automated unit tests. As a rule of thumb, you should have at least 90% code coverage. Effective testing may be really time-consuming for some teams, but this investment can help prevent costly mistakes in the future. You must also make sure that you have enough time for exploratory testing before deploying a new change as it can highlight any problems with the new code. The longer the testing phase, the more likely that problems will be detected.

  • Improve automated testing as part of your continuous integration process

Developers make changes to the code, create automated builds and tests, and release those builds with their developers, quality assurance (QA), testers, and eventually end users. Before you release a build of the software with the new code change, all previous builds should be tested continuously, using the latest code and configuration. Then, you can deploy that broken build to production or rely on manual testing. If a build fails due to a problem in new code, then you need to fix that problem quickly before going live with it again.

  • Do thorough and complete code reviews to help prevent issues from being introduced into production

Top of the line development practices should include code reviews with a small team of engineers. This ensures no coding standards are violated, that the code is reasonably secure, and that all breaking changes are caught. Once a new change has been released, it should be thoroughly reviewed by all members of the QA team, and any issues should be tackled as soon as possible. If new monitoring tools can detect issues early in the cycle, then this process may become more efficient.