Do you know how well your development team is performing? Do all deployments go off without a hitch? If not, it’s time to incorporate performance metrics such as the Change Failure Rate or CFR into your toolkit. CFR is a metric for measuring how often deployments or software updates fail.
If your team is deploying frequently, a high CFR can spell trouble. Therefore, it’s important to keep users in the loop with beautiful status pages by Instatus.
In this article, we define what CFR is, how to calculate and track it, comparing your team’s performance against others, and how to lower CFR without impacting deployment schedules.
We understand the challenges agile teams face with change failure rates (CFR). The in-depth and customizable monitoring tools offered by Instatus have helped numerous numerous businesses monitor and reduce these failures.
Case studies from our customers demonstrate significant improvements in deployment quality and reduction in CFR.
We help teams enhance their deployment processes, leading to more reliable releases and efficient incident management. Our tools empower teams to track, analyze, and mitigate change failures, resulting in higher productivity and improved overall performance.
Have you ever felt the need for speed? Sometimes success seems like it hinges on how quickly you can push out new updates and that it’s the only way to become a great development team. But that’s not always true. Quality matters as much, if not more, than deployment speed.
CFR measures the percentage of changes that cause service interruptions, outages, patches, or rollbacks. These incidents require developers’ intervention, and pulls them away from the next code release. Tracking CFR is the best way to learn about deployment quality.
Writing code isn’t easy, and creating code without bugs is even more challenging. If your CFR does not meet organizational targets, your code review and deployment process needs attention. Conversely, if the CFR is low, you can increase deployment frequency.
Calculating CFR is easy once you have proper monitoring systems. Any deployment that requires remediation or results in degraded service for users counts as a change failure. To calculate CFR, divide the number of failures by the total number of deployments over a period of time.
Here’s the formula to calculate CFR:
# of change failures / total # of deployments = change failure rate %
Once you’ve calculated CFR, compare it against the baseline to better understand your team’s performance:
If your team’s CFR is between 15% to 60%, it’s time to improve change quality.
CFR can be tracked over time by adjusting the time period. For example, to track CFR over six months and see if the team is improving or regressing, you can break the metric into two-month increments:
Jan - Mar: 33 failures / 100 deployments = 33% CFR
Mar - May: 22 failures / 100 deployments = 22% CFR
May - July: 14 failures / 100 deployments = 14% CFR
What does this result tell us? This team started on the lower end of medium-performance with a CFR of 33% or a third of deployments requiring remediation. However, over 6 months, there was a dramatic improvement, with the team reducing CFR to 14% or the elite performance category. Most deployments became high quality and no longer required rollbacks or hotfixes.
The overall six-month CFR for this team was:
Jan - July: 69 failures / 300 deployments = 23% CFR
If this team continues at this rate, it will achieve a CFR of less than 15% within the next six months.
It’s also possible to combine CFR with three other performance-based metrics, known as DORA, to quantify how well your team is performing.
The four DORA metrics are interconnected and improving the performance for one metric can degrade results for another, especially if the relationship isn’t understood. MTTR and CFR reveal information about the stability of your software and the strength of your incident response. At the same time, Deployment Frequency and Lead Time for Changes indicate how efficient your team is.
CFR is closely linked to Deployment Frequency. A balance between these two metrics is vital, but if your team over-emphasizes Deployment Frequency, developers may feel rushed to finish updates or push deployments. In such a scenario, code review and testing might also be rushed or skipped altogether. This can result in high-performing teams under the Deployment frequency metric, but it also means a high CFR percentage.
To get the full picture, you want to monitor all four DORA metrics together to understand your team’s performance over time. When your team decides to improve one DORA metric, take a calculated approach.
Now you know how to calculate the CFR. Here’s how to do it accurately.
1. Define the Metrics Clearly: It’s important to clearly define what constitutes a "change" and a "failure." A change typically refers to any system modifications such as code deployments, configuration changes, or infrastructure updates.
A failure is any change that results in inservice disruption or doesn’t achieve its intended outcome. Having clear metrics ensures that all team members are aligned and uniformly collecting data.
2. Track All Changes: A robust change management system will log every alteration. You can use version control systems like Git, deployment tracking tools, and automated deployment pipelines. Tag each change with relevant details such as the type of change, the time it was implemented, and who’s responsible.
3. Monitor Outcomes of Changes: You want to keep a close eye on any changes to see what issues arrise. Monitoring and alerting tools can track system performance and promptly detect failures. Logging systems can capture detailed information about system behavior post-deployment, which is vital for identifying and diagnosing failures.
Instatus integrates with third-party monitoring tools like Datadog, New Relic, and Pingdom to track incidents and link them to specific changes.
4. Record Failures Accurately: Failed changes must be recorded in detail. This includes the nature of the failure, its impact on the system, how long it took to detect the failure, and the time to remediate it. You can log these incidents systematically with tools like incident management systems.
5. Calculate the CFR: Calculate this by dividing the number of failed changes by the total number of changes over a specific period. The resulting percentages represents how many changes resulted in failures. Regularly updating and reviewing this metric helps in tracking performance over time.
6. Analyze Trends and Patterns: To gain insights into the underlying causes of failures, analyze the trends and patterns in the collected data. Focus on recurring issues, the common types of changes that fail, and any correlations between changes and failures. This analysis will highlight areas that need improvement and inform decision-making.
7. Report and Communicate: Regularly report the CFR to all stakeholders. Transparent communication ensures that everyone is aware of the current performance and can collaborate on improving processes. Visualizing the CFR through dashboards and reports can make it easier to understand and track.
If you want to improve your CFR, you must determine what’s causing failures. Most deployments fail because of one of three reasons:
Beyond CFR, it’s essential to find the root cause of a failure. Once you’ve collected enough data and categorized failures as either a deployment error, poor testing, or code quality, you can begin to address the problem. Remember to have a system, like Instatus, to update your user base on any service disruptions. Status pages maintain user confidence and trust while your team resolves these issues.
Most failed deployments are the result of human error. The best way to reduce such failures is through deployment automation. Incorporate deployment automation tools like Jenkins or Electric Flow as they will help meet the demands of continuous integration and deployment by removing the human element.
You should always be automating testing. Automated testing provides enormous returns for your team as it removes the need for slow and expensive manual testing. This means developers have more time to write high-quality code and work on other creative efforts. Storybook, Jest, and Postman are some great options to get started with automated testing.
To improve code quality, ensure you have a code review process in place. Junior developers should be mentored and have all their written code reviewed. This is not a punishment, and since your team is only as strong as your weakest link, make it a positive experience. Senior developers should systematically review code and ask lots of questions.
Your business won’t perform well if you can’t reduce the CFR. Here are some ways to reduce the CFR and improve your business.
1. Comprehensive Testing: To reduce the likelihood of failures, rigorously test all changes before deployment. This includes unit tests, integration tests, system tests, and user acceptance tests. Automated testing frameworks can run extensive testing suites efficiently and consistently.
2. Adopt Continuous Integration and Continuous Deployment (CI/CD): CI/CD practices enable frequent and smaller deployments, which are easier to manage and less likely to introduce significant issues. Through this, teams can detect and fix issues earlier in the development cycle,which reduces the risk of failures.
3. Use Feature Flags: Feature flags allow teams to deploy changes to production without immediately activating them for everyone. This enables controlled testing and the gradual rollout of new features. It also minimizes the impact of potential failures. If you detect an issue, you can turn off the feature without rolling back the entire deployment.
4. Thorough Code Reviews: Peer code reviews identify potential issues before changes are merged into the main codebase. Encouraging a culture of thorough and constructive code reviews improves code quality by having more than one person checking for defects.
5. Improve Rollback Capabilities: Develop effective rollback procedures to quickly revert changes that cause failures. Automated rollback mechanisms can restore the previous stable state with minimal manual intervention, reducing downtime and the impact on users.
6. Enhance Monitoring and Observability: Implement comprehensive monitoring and observability tools to gain real-time insights into system performance and detect issues early. Tools like Prometheus, Grafana, and ELK stack (Elasticsearch, Logstash, Kibana) help quickly diagnose problems.
There are existing guidelines and strategies that organizations can adopt to minimize the risk of failure during the implementation of changes. By following these best practices, organizations can ensure smoother transition, reduced downtime, and improved overall efficiency in their operations.
It's vital to thoroughly collect and tag data to ensure effective integration of the CFR system with your IT processes. Define the precise scope of the changes you wish to implement and outline the specific areas that need attention.
Additionally, establish the criteria for measuring failure and success for aspects of your CFR that may require further optimization.
Fix-only deployments" in Change Failure Rate (CFR) refer to a practice where changes are implemented solely to address issues or failures that have already occurred without proactively identifying and resolving potential underlying problems.
Excluding "fix-only" deployments from the calculation of the CFR will provide a clearer picture of the stability of your IT system, free from the influence of remediation efforts. If it's impossible to leave out “fix-only” deployments, define its number solely for remediation and do not include it in the calculation of the CFR.
Deployment failure happens when workflows, code, and updates fail to be successfully deployed into the production environment. This will indicate the quality of your Continuous Integration/Continuous Deployment (CI/CD) pipeline. It shows how well your code gets from development to production.
Whereas, CFR has a broader concept that includes not only deployment failures but also any negative impact that changes might have on the production environment. It takes into account both unsuccessful deployments and any incidents that arise from those changes.
To correctly calculate the change failure rate, you need to connect incident data with deployment data to better understand the impact your changes have on the stability of your software in the production environment.
Excluding external links provide a more accurate and meaningful measure of the success and stability of code changes. The change failure rate is a metric used to track how often code changes result in failures or issues in the production environment.
Including external links, such as those pointing to third-party services or APIs, in the calculation can skew the results and give an inaccurate representation of the actual code quality.
By excluding external links from the change failure rate calculation, the focus remains on the code changes directly developed and deployed by the team.
While DORA metrics can provide valuable insights, they should not be the sole measure of a team's success. It is important to note that it only serves as a starting point for understanding team performance.
For a more comprehensive view, you should consider additional performance indicators to account for the specific complexities of the IT systems and development processes.
Not limiting yourself to the DORA metrics can help you gain a better understanding of the team’s capabilities and areas for improvement. This would lead to more effective strategies for enhancing software delivery and development practices.
Your customers expect a high-quality product, and you don’t want to disappoint. A great way to stay on top of everything by monitoring your team’s deployments through CFR.
Ideally, you want zero rollbacks or service interruptions, but the unexpected can happen no matter how good your code review, testing, and deployment automation is.
That’s why it’s important to keep users informed with status pages from Instatus, while aiming for a 15% or less CFR. Find the balance between CFR and Deployment Frequency that works for you, and success will follow.
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