Standard : Code Review Cycle Time

Description

Code Review Cycle Time measures the amount of time between when a pull request (PR) is opened and when it is approved and merged. It reflects how responsive your teams are to peer contributions and how efficiently changes move through the review process.

Reducing code review cycle time leads to faster feedback loops, fewer context switches, and a smoother developer experience—without sacrificing quality.

How to Use

What to Measure

  • Time from PR creation to merge, split into stages if possible (e.g. time to first review, time to approval, time to merge).
  • Optionally exclude draft or WIP PRs for cleaner insights.

Formula

Code Review Cycle Time = PR Merge Time – PR Open Time

Instrumentation Tips

  • Track using version control platforms (e.g. GitHub, GitLab, Bitbucket).
  • Visualise trends per team, service, or developer.
  • Use tags to separate code types (e.g. feature, bug, refactor) for comparison.

Why It Matters

  • Flow efficiency: Delays in review slow down delivery and feedback.
  • Developer experience: Long waits lead to frustration and context switching.
  • Quality feedback: Timely reviews support better engineering discussions.
  • Team engagement: Healthy review cultures build shared ownership.

Best Practices

  • Define service-level expectations (e.g. respond to PRs within 1 business day).
  • Automate notifications and triage to reduce review queue time.
  • Encourage smaller PRs for faster, more focused reviews.
  • Track PRs waiting too long and raise in stand-ups or retros.
  • Use async and sync reviews (e.g. pairing, office hours) where helpful.

Common Pitfalls

  • Review bottlenecks due to unclear ownership or overloaded reviewers.
  • Huge PRs that are hard to review in one sitting.
  • Ignoring non-merged PRs in metrics.
  • Rushing through reviews to “hit numbers” instead of improving quality.

Signals of Success

  • Most PRs receive a review within 24 hours.
  • Merge-to-open time is predictable and trending downward.
  • Engineers feel confident in the speed and fairness of the review process.
  • Review practices support quality, learning, and fast flow.
  • [[Cycle Time]]
  • [[Lead Time for Change]]
  • [[Pull Request Throughput]]
  • [[Code Quality Score]]
  • [[Work in Progress (WIP)]]