rnd-decompositionlisted

# R&D Decomposition ## Overview Decompose tasks into structured sub-task trees. Every sub-task gets a pre-registration document with testable success criteria BEFORE any code is written. **Core principle:** If you can't write testable success criteria, the task isn't understood well enough to build. ## When to Use - Planning phase of `/rnd-framework:rnd-start` or `/rnd-framework:rnd-plan` - Any non-trivial feature, refactor, or task with multiple moving parts or unclear success criteria ## The Iron Law ``` NO CODING WITHOUT PRE-REGISTRATION ``` ## Hierarchical Decomposition ``` System Level: [Feature] <-> [System Validation] Module Level: [Components] <-> [Integration Tests] Unit Level: [Functions] <-> [Unit Tests] ``` 1. Start at System level — what does the feature DO end-to-end? 2. Identify Modules — what components are needed? 3. Break into Units — what functions/utilities does each module need? 4. Pair each level with verification — system validation, integration tests, unit tests A criterion is testable if a skeptical Verifier can evaluate it from evidence alone: **observable outcome** (return value, state change, error thrown), **concrete conditions** (specific inputs, thresholds, error types), **binary result** (met or not met). ### Decomposition Heuristics - **Too big:** >5 success criteria → split - **Too small:** single function with one criterion → merge up - **Too vague:** "works correctly", "handles errors" → rewrite with observable outco