Spec-Driven Development with GitHub Spec-Kit: Planning Phase
A comprehensive guide to the critical planning phase review process in spec-driven development. Learn what engineers should do after creating a technical implementation plan but before running the /tasks command to catch issues early.
GitHub Spec-Kit generates comprehensive technical implementation plans after you define your feature requirements. However, the tool generates multiple files and complex technical decisions that require careful review. This critical planning phase review ensures the generated plan aligns with your project's needs before proceeding to task generation and implementation.
Work in Progress Notice
GitHub's spec-kit is still actively being developed and improved. While it's a powerful tool for spec-driven development, expect occasional breaking changes and updates to the API.
update-agent-context.sh script in PR #598 This article focuses on the critical Planning Phase Review in spec-driven development. After you've completed Step 4: Create a technical implementation plan but before running the /tasks command, you need to carefully review your generated plans to catch issues before code implementation begins.
You Are Here in the Process
1. Feature Specification Review
File: /specs/[feature-name]/spec.md
What to check:
- User stories match what you actually want
- Technical constraints are accurate
- Success criteria are realistic
- Timeline estimates make sense
Key sections to review:
- User Stories (US-1 through US-N)
- Functional Requirements (FR-1 through FR-N)
- Technical Constraints (TC-1 through TC-N)
- Out of Scope items
2. Technical Decisions Review
File: /specs/[feature-name]/research.md
What to check:
- Library choices make sense for your project
- Integration approaches are feasible
- Security measures are appropriate
- Performance targets are achievable
3. Database Changes Review (CRITICAL)
File: /specs/[feature-name]/data-model.md
What to check:
- Schema changes don't break existing data
- New tables are actually needed
- Migration approach is safe
- Indexes are appropriate
Database Issues
- • Over-engineering: Too many new tables/columns
- • Breaking changes: Modifications affecting existing features
- • Performance: Missing indexes or inefficient queries
Integration Issues
- • Service conflicts: Changes breaking existing integrations
- • User ID changes affecting payments or data
- • Transition plans that are too disruptive
Scope Issues
- • Feature creep: Functionality beyond original request
- • Missing features: Core requirements not covered
- • Timeline: Unrealistic implementation estimates
Review the specification files in order
Start with spec.md, then research.md, followed by data-model.md
Request changes if needed
Provide specific feedback on what needs to be modified
Generate implementation tasks
Once satisfied with the plan, generate specific implementation steps
Execute the tasks
Implement the feature following the generated task list
This planning phase review sits at the most critical juncture in the spec-driven development process. You've invested time in creating specifications and GitHub Spec-Kit has generated comprehensive implementation plans. Now, before running /tasks to create 25-30 specific implementation steps, this is your last chance to catch fundamental issues.
⏰ Perfect Timing: Changes made during this review phase take minutes. Changes made after code implementation begins take hours or days.
The planning phase review is your opportunity to catch issues before the /tasks command generates implementation steps and before any code is written. It's much easier to change the plan than to refactor code later. This critical phase ensures that what you build matches what you actually need, reducing waste and improving development velocity.
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