In software development, no code is written in stone. It's common to make changes to your own code halfway through the project or after the code is pushed into production, either to include new requirements or improve some newfound quality issues. While these changes can be helpful to some extent, too much of anything is bad. Tracking, measuring, and evaluating these code changes can help you improve your code quality and team performance, while predicting future risks. This is what code churn is all about. 

In this article, let us discuss what code churn is, how to measure it, and how it can help improve code quality:

What is Code Churn & How to Measure It?

Code churn, also known as "rework," is a code quality metrics that indicates how often changes are made to a specific piece of code, including a file, a class, or a function, during the development cycle. It occurs when a developer rewrites, modifies, or deletes code they have written recently (usually within the first 2 to 3 weeks), either to enhance code functionality or structure. 

Code changes are a natural part of software development as code is tested and refined regularly, especially during problem-solving or trying out new code. It enables developers to maintain software, fix bugs, push new iterations, release updates, and add new features. Moreover, if older, longer code is changed to a new, simpler code, the room for bugs will be decreased drastically, saving your team’s valuable time and effort. However, code churn in high volumes indicates underlying problems affecting the development team. 

Code churn should be kept to a minimum, especially before the release. In general, high levels of code churn indicates code instability. During the initial phases of the software development cycle, there will be many additions, modifications, and deletions to a piece of code, so you can expect high rates of churn. However, towards the end of an iteration or before a release, the level of churn should go down. 

Moreover, excessive code churn may indicate that a developer is struggling to write that given piece of code. The reasons behind the struggle can be many. One of the prominent reasons is a lack of skill or knowledge. Another common reason is the lack of proper communication between the team and the client, which results in ambiguity in the project requirements, causing the feature to be rewritten several times. Burnout and retention/turnover issues, frequent change requests from external stakeholders, and the quest for perfect code are some of the common reasons for high code churn. 

That said, there’s no baseline or threshold value for an acceptable level of code churn. As with most code quality metrics, code churn varies from one developer to another, from one team to another, or from one project to another. There's no standard level of code churn that can be universally applied to all developers. 

As per industry experts, an overall code churn of about 15-25% is acceptable to most teams, with 15% or less being a sign of normal to highly efficient teams.

Why is Measuring Code Churn Important?

You can’t improve what you don’t measure. So, the first step to managing and minimizing your code churn is measuring it. By meticulously tracking and measuring this metric, you can be well prepared to take things into control when the code churn starts to get out of control. You need to define the acceptable churn levels among your DevOps team, so that you can easily identify the incidents and areas where it exceeds these levels. This enables you to understand the entire software development process and the people involved—both the DevOps team and the client. As said in the earlier section, measuring code churn helps identify the number of times code is changed, which provides insights into the internal and external hurdles such as the quest for perfection or unclear client requirements. Here are some other factors that make measuring code churn an imperative aspect:

• Code churn can be a symptom of scope creep, as excessive churn sometimes results from the addition of new requirements that were not in the project scope initially. 
• Code churn helps understand the nature of the feature in development. For example, a new feature may require several iterations to become fit for release, resulting in high code churn. 
• Code churn also indicates the level of understanding of the deliverables, as ambiguous objectives may require multiple iterations. 
• Code churn provides insights into the bottlenecks in the software development process so that you can address them and relieve stress on developers. 
• Code churn also helps understand the workload distribution, so you can optimize resource allocation by identifying the code areas that require multiple changes and more testing. 
• Measuring code churn also helps understand if the development team requires any push in the deadline and saves last-minute delays. 
• Tracking code churn helps in defining a base for estimating future code maintenance efforts in order to plan software maintenance activities, which is a keystone of software project planning. 

Here are the top DevOps metrics that you need to measure to improve your code quality: https://www.opsera.io/blog/you-cant-improve-what-you-cant-measure-13-kpis-necessary-for-every-devops-leader  

Top 5 Metrics to Measure Code Churn

As stated in the earlier sections, code churn occurs when the developer rewrites, modifies, or deletes, some sections of code or the entire code within 2 to 3 weeks of writing it. This code churn can indicate something good like code refactoring or bad like development hurdles. However, it can only be identified after the code churn rate is measured. So, here are the top 5 metrics that you need to track to measure code churn: 

1. Code Churn Count: This is the measure of the number of times the development team made changes to a file in the version control
2. Lines Added: This is the number of lines of code the developers added to files for the code that was written recently
3. Lines Deleted: This metric is the measure of the number of lines of code that were deleted from files by the developers within three weeks of writing the code
4. Lines Modified: This metric is the measure of the number of lines of code that were modified by the developers within 3 weeks of writing the code. 
5. Total Code Churn: The total code churn is the addition of Lines Added, Lines Deleted, and Lines Modified. 

So, how can you measure these metrics, apart from the 13 code quality metrics that you must track?

Opsera’s Unified Insights tool is a powerful DevOps metrics dashboard that enables you to aggregate all the code quality metrics into a single, unified view. It helps gain end-to-end visibility into the metrics in true CI/CD categories, including Pipelines, Planning, SecOps, Quality, and Operations. Moreover, this persona-based dashboard provides code quality analytics targeting vertical roles, including developers, managers, and executives, to empower you to understand your DevOps processes from both practitioner and managerial perspectives and take better technical and business decisions. The platform provides fully aggregated and contextualized logs and reports, that help you to easily analyse the metrics and identify the issues in the code faster. The actionable intelligence empowers you to troubleshoot the code issues within no time. After all, Unified Insights Tool is built for improving code quality and efficiency. 

How to Predict Risk and Mitigate Code Churn

Now, you know what code churn is all about, how it impacts code quality, and the underlying problems it indicates in your codebase. The next step is to know how to mitigate code churn in your DevOps projects. Here are some of the ways you can manage your team’s code churn:

1. Define Project Requirements Properly 

Most issues arise from not taking sufficient time to properly understand and define a project's requirements. The better you define the requirements of the project, the less the code churn owing to mid-stream changes. However, this demands seamless collaboration and communication between stakeholders, clients, and the development team. You need to ensure that all the people involved in the project are on the same page before commencing the work. It's better to educate the client and the stakeholders on how mid-stream changes slow delivery and increases time. 

2. Implement Coding Standards & Style Guides 

Usually, the developers spend more time reading code than writing it. On this basis, you need to make your code readable for everyone. However, every developer is different. They have their own professional qualification and work experience. Their language preferences and writing style are also unique. This is where standardization comes in. 

Implement a coding standard for your team and make it clear to them that they should follow these standards to write the code. Also, select coding style guides. This makes reading code easier and faster for everyone. Consequently, you can expect less code churn across all your projects. 

3. Manage Perfectionists 

Developers who strive for perfection can produce excessive code churn. It's a great developer quality, but not a great coding practice. This presents a challenge to manage perfectionists. While you want your developers to continuously strive to write better code, you must also make them understand the software development process. Educate them on how fixating on perfect code results in a cascading impact on the team productivity and project deliverables. Help them understand that the software development process aims to produce new releases continuously and consistently, while meeting client requirements, schedules, and budget. Let them push good code out fast now, and you can improve it later, in a controlled manner. Educate your perfectionists to get the big picture. After all, perfection is a mirage. 

4. Control Experimentation 

Experimentation is fun for developers. However, it can significantly increase code churn. Some of your developers may experiment or reinvent the wheel to create new solutions to problems that already have plenty of time-tested, stable solutions. Here, you need to make it clear to your developers about the resources they can use. 

Software libraries make programming easier, wherein, developers don't have to regularly reinvent the wheel. There are over 180,000 open source projects available. So, your developers can simply apply the logic from other projects to fit their requirements. 

Benefits of Measuring the Code Churn

In the previous sections, we already discussed why measuring code churn is important for DevOps teams. Now, let’s discuss the business benefits that you can realize by measuring the code churn: 

1. Maintaining the proper code documentation

No software project is complete without proper code documentation that explains how code works and how to use it. Accurate and complete documentation throughout the DevOps lifecycle empowers developers to maintain a codebase as it enables them to quickly understand what the code does and how to work with it. Clear code descriptions or comments are crucial for establishing seamless collaboration across teams, especially for new team members and developers from other organizations, such as customers or partners. Code documentation is also useful for the same developers who created the code, as they may often come back to it weeks, months, or years later. But software development is evolving rapidly. Each new iteration brings changes, fixes, and new features that demand updates in the documentation. This is where measuring code churn helps in maintaining proper code documentation. Code churn indicates something might be wrong with your development process and might be a symptom of deeper problems with the code design and structure. Measuring code churn helps understand and address these underlying problems and update the code documentation properly. 

2. Consistent code reviews

Excessing code churn can be the result of suboptimal code reviews and testing processes. If your team has implemented a review process, but many code errors and issues go unnoticed, that’s a sign that your review process should be improved. So, if your code churn is high, it’s time to analyse the capability of your existing code review processes and improve them if they are not up to the mark. This is how measuring code churn helps you implement efficient and consistent code reviews. 

3. Choosing the right refactoring technique

Code refactoring is typically not included in the core phases of the software development lifecycle. However, you cannot skip it if you keep your code running efficiently. Even seemingly perfect code now can progressively decay over time, given the ever-evolving IT world. Small minor issues can gradually pile up and become severe enough to incur huge system inefficiencies and high maintenance costs. Code refactoring helps maintain long-term code quality, security, and performance. It provides greater readability and enhances the maintainability of the code. Here, the code churn helps prioritize code refactoring that is important and urgent. Code sections that are frequently changing are the ones that cause the most problems. Thus, measuring this kind of metric can help you identify code hotspots that need to be attended first in any refactoring efforts. It also helps you understand the underlying problem and choose the right refactoring technique to address it. 

4. Quality of Code Standardization

Measuring code churn helps you understand the quality levels of your code. When code churn is high, meaning the low quality of code, you can comprehend that you need to handle the underlying causes for frequent code changes. Whether it is design and architectural flaws in the application, developers lacking skills, or unclear requirements from the client, you need to address the root cause of code churn to achieve reliable, secure, and safe code. The insights from the code churn metric help you work on the code quality standards that developers need to implement to produce efficient, readable, and cleaner code with minimal or no errors. 

Best Tools for Measuring Code Churn

Realizing the business benefits of measuring code churn (mentioned in the above sections) is easier said than done. You need to leverage the right set of tools to accurately measure the code churn and glean useful insights. As there are many tools (both open-source and subscription-based) available in the market, you need to be mindful while choosing the tools based on your requirements. This is where Opsera comes in. Our huge industry experience, deep domain expertise, and global presence set us apart to help you implement and utilize the best tools. Here are some of the best of breed tools for measuring code churn:

1. Git 

Git is a free and open source distributed version control system designed to handle everything from small to large projects with speed and efficiency. It will connect to the git repository and gleans insightful metrics for a given date period. Some of the metrics measured by the git tool are:

• Number of code lines added
• Number of code lines modified
• Number of code lines deleted
• Number of files changed
• Total code churn 

2. Jira 

Jira is a change management / enablement tool that can help you move from traditional change management processes to a modern change management practice. It ensures that you record, assess, approve, and implement change requests. With this tool, you can schedule and track changes that are happening, thereby reducing code churn risk and streamlining your change management processes. The automation feature of the tool can be used to calculate the level of risk of each change request and set the appropriate risk value.

You can also leverage Jira to:

• Classify a change request as 'standard,' 'normal,' or 'emergency' 
• Route change requests down the right Jira workflow path - pre-approvals for standard changes and additional workflows for high-risk normal changes
• Notify assigned stakeholders about high-risk changes which require further review

3. GitHub

GitHub is a source code management tool. It allows your development team to track, manage, and review the changes made to the code base. It is available in both free and paid packages. While the open-source tool comes with the basic feature of source code management, the paid version of the tool comes with advanced features such as GitHub Copilot, an AI-powered tool that helps you write better code through suggestions.

How Opsera Can Help You Reduce the Code Churn in DevOps?

Opsera’s Unified Insights tool is a powerful DevOps metrics dashboard that enables you to aggregate all the code quality metrics, including code churn metrics, into a single, unified view. This helps you gain end-to-end visibility into the code changes in a given time period. Moreover, this persona-based dashboard provides code quality analytics targeting vertical roles, including developers, managers, and executives, to empower you to understand the factors resulting in high code churn. Our clear actionable intelligence can help you spot where the problem is in your code and improve code churn. 

Seeing Excessive Code Churn in DevOps? Opsera Can Help!