The average time between when a pull request is opened and when it received its first review. In calculating the average, each pull request is counted once (not as many times as there are reviewers).

Time to First Review excludes self-reviews.

Why it matters: This represents that amount of time, on average, that a submitter is left waiting for feedback. When this metric is high, submitters either waste time waiting or are compelled to open up multiple tracks of work. This results in an increase in their team’s inventory, which, in turn, negatively impacts Cycle Time. 

How to use it: If the Time to First Review is elevated, consider aligning on what the code review expectations are and how reviews can better be integrated into the day-to-day.