implementation-planning_skill

Overview

This skill creates actionable implementation plans that break features into executable tasks following TDD principles. It produces implementation-plan.md files that map PRD acceptance criteria and SDD components to verifiable deliverables. Plans make dependencies explicit, identify parallel work, and include validation gates for specification compliance.

How this skill works

The skill reads the PLAN template and the relevant PRD/SDD sections, then generates a structured plan using Prime → Test → Implement → Validate steps for each task. Each task is a trackable unit that produces a verifiable outcome, includes specification references and activity metadata, and declares sequencing and parallelism. The final output follows the prescribed template and a PLAN status summary that highlights phases, task counts, and coverage metrics.

When to use it

• Creating a new implementation-plan.md from the template for a feature or spec
• Defining or completing phases in an existing implementation-plan.md
• Sequencing tasks and analyzing dependencies before development starts
• Planning TDD cycles and embedding validation gates into tasks
• When you need every PRD acceptance criterion and SDD component mapped to deliverables

Best practices

• Treat each task as a logical unit that yields a verifiable deliverable, not an activity
• Always include [ref: ...] links to PRD/SDD sections in Prime steps for traceability
• Embed Test-first criteria that reference PRD acceptance criteria and edge cases
• Mark concurrent work with [parallel: true] and ensure no circular dependencies
• Include a Validate step per task or a Phase Validation task to gate specification compliance

Example use cases

• Break a new payment feature into entities, adapters, and UI components with tests and validation
• Define backend API workstreams with clear sequencing, parallel groups, and test-first tasks
• Convert SDD components into implementation tasks that a developer can follow independently
• Plan an integration phase that includes E2E tests, lint/type checks, and spec validation
• Update an implementation-plan.md after a discovery phase to reflect new dependencies