[Metric] Lead Time by Stage

[chrisma]

Software.com's product includes the notion of "stages" for which lead times can be computed:

By measuring lead time across the stages of your delivery pipeline, you can spot bottlenecks and identify areas for improvement

Definitions

Stages are defined as:

• Develop: first commit on a branch to when a pull request is opened for that branch.
• Review: pull request opened to first review.
• Approval: first review to first approval.
• Merge: first approval to merged to trunk/main.
• Release: merged to released to production.

Questions

• How does this deal with PRs marked as drafts? Would more general categories work better?
• Release → Merged to main (What constitutes a "release" might be very different for projects)