Design phase playbook
How Phase 2 runs: from a signed-off PFD to a build-ready design pack. The Design Review gate is the exit checklist; this is the method.
The sequence
- UX flows (template) — cover every PFD scenario, including error and empty states.
- Data model (template) — generated from flows, reviewed by Data + Security.
- Key screens (template) — mapped to design-system components and tokens.
- Clickable prototype — for SME validation (throwaway; validation only, must not leak into Build).
At each step: the relevant design prompt/skill drafts (e.g. design-crit), SMEs check at defined points, and the work is time-boxed.
Also at Design: the per-feature STRIDE pass (threat modelling) and the risk-based test plan — both complete before the Design Review gate.
Open decision this depends on
Design tooling — code-first prototypes vs Figma-first (with token export / MCP into the agent workflow) vs hybrid — is an ADR that must be settled before StudyBuddy, because it shapes every design template and skill. (This is a decision for the design + engineering leads — flagged, not assumed.)
Prototype speed must not become Build's foundation — the design pack, not the prototype, is what Build receives (the full validation-not-production discipline lives in SME design validation).
Standards referenced: ISO 9241-210.