Change failure rate is up 30% — here's how to measure yours in an afternoon

A practitioner's guide to calculating your team's CFR without a vendor platform — the DORA formula, the SQL, and the AI-assisted vs human-authored split nobody is publishing yet.

Cortex's 2026 benchmark says change failure rate has risen about 30% industry-wide since AI coding adoption accelerated. The number has been quoted in every engineering newsletter I read. It keeps showing up in LinkedIn posts. I cited it myself in my last post.

Here's the uncomfortable follow-up question: what's yours?

Most platform teams I've worked with couldn't give me a number. They could estimate a direction — "it feels worse lately" — but the actual percentage wasn't anywhere. And without a number, the 30% headline is just other people's data. You can't improve what you haven't measured.

This post walks through how to compute your team's CFR in an afternoon using data you already have, and how to split it in a way nobody is doing yet: AI-assisted PRs vs. human-authored. You don't need a vendor platform for any of this.