Review time

What is review time?

Review time refers to the duration spent on the code review process, which begins when a developer submits their code for review and ends when the code is approved for merging. It includes all the activities involved in scrutinizing the code for correctness, performance, adherence to coding standards, and compatibility with existing systems. The calculation of review time can be straightforward: it is the difference between the time of code submission for review and the time when the code is finally approved to be merged into the main codebase. This metric is recorded in units like hours or days, depending on the length of the review cycle.

Why is review time important?

Ensures code quality. Review time is crucial because it directly impacts the quality of the code. A thorough review process helps identify potential errors, bugs, or issues that might not be evident to the original coder. By dedicating adequate time to review, teams can ensure that only well-vetted and high-quality code is integrated into their products, leading to more reliable and stable software.

Facilitates knowledge sharing. Review time also serves as an opportunity for knowledge transfer among team members. Through the review process, developers can share insights and alternative approaches, enhancing the team’s overall coding skills and understanding of the project. This collaborative aspect of code reviews not only improves the code being reviewed but also contributes to the professional growth of the developers involved.

Predicts project timelines. Tracking review time helps in predicting more accurate project timelines. Understanding how long code reviews take can aid in better planning and resource allocation, ensuring that projects stay on schedule. This is particularly important in complex projects where delays in one phase can impact several other dependent tasks.

What are the limitations of review time?

Does not measure quality directly. While review time can indicate the thoroughness of a review, it does not directly measure the quality of the output. Longer review times do not necessarily result in better code, as they might also reflect inefficiencies or lack of expertise within the review team.

Varies widely across tasks. Review time can vary significantly depending on the complexity of the code, the experience of the reviewers, and the specific standards set by the team. This variability makes it difficult to standardize review times or use them as a benchmark across different teams or projects.

Potential for diminishing returns. There is a point beyond which increasing the time spent on reviews does not yield proportional benefits. Excessively long review processes can delay the project and may lead to diminishing returns in terms of code quality improvement, especially if the code is relatively straightforward or if the reviewers are not effectively identifying issues.

Metrics related to review time

Cycle time. Cycle time is the total time from when work starts on an item (like a feature or bug fix) until it is ready for delivery. Review time is a crucial component of cycle time as it influences how quickly a piece of code moves from development to being ready for production. Shortening review time can significantly reduce overall cycle time, leading to faster delivery times.

Merge time. Merge time is the duration it takes to integrate code changes into the main branch after they have been approved in a review. This metric is closely related to review time because any delays or inefficiencies in the review process can directly extend the merge time, affecting the speed at which new features or fixes are available in the main codebase.

Review depth. Review depth measures the thoroughness of the code review process. It examines factors such as the number of issues found, the severity of the issues, and how comprehensively the code has been analyzed. Review time can influence review depth, as more time could potentially lead to more thorough reviews, although this is not always the case depending on the efficiency and skill of the reviewers.