MoSCoW prioritization is a backlog triage method that sorts work into four buckets: Must-have, Should-have, Could-have, and Won't-have. It's built for teams staring at a long list with no obvious starting point.
Must-have means the product doesn't ship without it. Should-have means important, but you could survive one release without it. Could-have means nice to have if time allows. Won't-have means explicitly out of scope for this cycle.
Why the Won't-have bucket matters
Won't-have isn't a trash can. It's a decision. Explicitly calling something out of scope stops teams from relitigating it in every planning meeting. That alone saves hours.
Where it breaks down
The failure mode is when everything ends up in Must-have. If more than 30-40% of your backlog is labeled Must, your team hasn't made real decisions yet. Push back. Ask: "What actually breaks if we ship without this?"
MoSCoW also doesn't account for effort. A quick win and a six-month epic can both be Must-haves. Pair it with effort estimates to do real planning.
It works best at the start of a planning cycle or when scoping something new. Use FeatureOS's MoSCoW tool to keep everyone on the same page.