SUC stands for Suboptimal Usability and Comprehension. An audit that dumps ninety issues on a team gets deprioritized — tell leadership "these four issues are costing us users this week" instead, and they act. This field guide is the framework behind that sentence.
First presented at A11yTalks in January 2025 and tested with 43 blind and low-vision participants, the SUC score is not a standard or a guideline — it's a way to take the pile of issues an audit hands you and answer three questions the report usually doesn't: which are losing you users right now, which are cheap to fix, and in what order should engineering attack them.
Why audits end up on the back burner
An audit report records the severity of every issue. It doesn't record where the issue lives, what it actually does to a user, or how cheap it is to fix — so a missing label on the "Pay now" button and a missing label on "Link your Facebook account" show up as one ticket each. Counting issues is a misleading way to track accessibility: tell a leadership team "we have 90 issues" and they'll deprioritize the sprint. Tell them "these four issues have a 100–200% chance of losing every screen-reader user who hits them this week" and they fund it.
Who is this for?
Product owners & managers
Read the chapters on why audits stall, location (core/necessary/auxiliary flows) and fixing in order. You own sorting the flows and the ROI conversation with leadership.
Designers
Read the chapters on severity, the Suckiness Index and lowering the score before the audit even starts. Two thirds of the issues in a typical audit trace back to the design phase.
Engineers
Read the chapters on the ease-of-fix rule and how to read a SUC-scored audit. You get two jobs — call the easy fixes, work the grid — and one veto on stale issues.
Impact Potential
- Turns a report of ninety issues into a handful of numbers leadership already tracks — monthly and weekly active users
- Standards-agnostic — layers on top of WCAG 2.1, 2.2, ATAG or house rules, so it doesn't compete with whatever audit process is already in place
- Built-in prioritization means the grid is the backlog order — no second framework needed to decide what to do with the score
- Honest about its limits: the indices come from 43 vision-impairment participants and are explicitly labelled a strong opinion, not a law — cognitive-impairment scoring is still being researched