Closes #6.\n\nImplemented with OpenCode and specialist research; corrected and binding-reviewed by Jasper.
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MoSCoW Prioritization
A method for aligning a team on scope for a specific time-boxed delivery. Every item is classified into one of four buckets. Developed by Dai Clegg at Oracle UK (1994) and later adopted by the DSDM Consortium.
Source: Wikipedia: MoSCoW method
The Four Categories
Must Have
Non-negotiable. Without these, the release has no value. If a Must Have slips, the date slips.
Test: "If we ship without this, would we regret delaying the whole release?"
Examples: Authentication for a login-required product. Payment processing for an e-commerce launch.
Guidance:
- DSDM commonly recommends keeping Must Haves near or below 60% of expected effort to preserve contingency; treat this as a planning heuristic, not a universal allocation
- If everything is Must Have, nothing is Must Have — push back
- Must Haves are the first thing built and the last thing cut
Should Have
Important but not vital. These deliver significant value and should be included if possible, but the release is viable without them.
Test: "If we ship without this, will users notice? (Yes, but they won't leave.)"
Examples: Secondary sort options on a search results page. Email notifications for account changes.
Rules:
- Should Haves are the first to get descoped when Must Haves overrun
- They should have a clear workaround or fallback
- A Should Have that survives 2+ consecutive releases without being built is probably a Could Have
Could Have
Nice-to-have. These are the first to cut when time runs short. Including them is a bonus, not an expectation.
Test: "If we ship without this, would anyone actively complain?"
Examples: Custom themes. Advanced filtering. Keyboard shortcuts.
Rules:
- Could Haves are where you put your stretch goals
- Zero shame in cutting every Could Have
- If a Could Have generates repeated stakeholder pressure, it's probably misclassified
Won't Have (This Time)
Explicitly out of scope. The most important category — it makes the other three meaningful by establishing a boundary.
Test: "Are we confident we won't build this even if we finish early?" (If yes, it's a Won't Have. If no, it's a Could Have.)
Examples: Cross-platform sync in v1. Admin dashboard for a v1 consumer product.
Rules:
- Won't Haves get a reason and a potential timeline ("v2 if we hear demand")
- They protect the team from scope creep by making the boundary explicit
- Revisit every quarter — some Won't Haves become Must Haves as context changes
An Illustrative Capacity Heuristic
| Category | Illustrative capacity |
|---|---|
| Must Have | 60% |
| Should Have | 20% |
| Could Have | 20% |
| Won't Have | (not allocated) |
The 60/20/20 split is DSDM guidance for maintaining contingency, not a formula that proves a plan is viable. Adapt it to the delivery context and confidence in estimates. If Must Haves consume nearly all expected capacity, make the tradeoff explicit:
- Cut scope — move some to Should Have or Won't Have
- Extend timeline — but be explicit that this is the tradeoff
When to Use MoSCoW vs RICE
| Use MoSCoW When | Use RICE When |
|---|---|
| Scope is fixed (deadline-driven release) | Effort is fixed (you can build anything, within capacity) |
| You need crisp boundaries for a team | You need defensible priorities for stakeholders |
| Items are all in the same problem space | Items span unrelated domains |
| The team needs a shared understanding of scope | You need a numerical comparison to settle disagreements |
The Anti-Pattern
Everything is a Must Have. This is the most common failure mode. It means nobody trusts that Should Haves will actually get built, so everyone pads their requirements. The fix is to demonstrate that Should Haves really do get built — which means actually cutting something on the Must Have list first.
If a stakeholder insists everything is Must Have, write the items down, compare them with available capacity, and ask which ones should move if the estimates or date cannot change. This reframes the constraint from abstract to concrete without pretending the illustrative ratio is an observed capacity limit.