Requirements Definition

Methodology for requirements definition ensuring comprehensive specification before implementation.

Investigation Workflow

1. Directory structure - Glob
2. Symbol analysis - get_symbols_overview
3. Keyword search - Grep or find_symbol
4. Dependency mapping - find_referencing_symbols
5. Specific content - Read
6. Latest API docs - Context7

Question Scoring

Score each unclear requirement (1-5 each):

Critical questions (score >= 15): Must answer before proceeding.

Example:

Question: "Should we use TypeScript's strict mode?"
- Design Branching: 5
- Irreversibility: 4
- Investigation Impossibility: 3
- Effort Impact: 4
Total: 16 (critical)

Question Types

• Spec confirmation: "Does API return null or empty array?"
• Design choice: "REST or GraphQL?"
• Constraint: "Must support IE11?"
• Scope: "Include admin features in v1?"
• Priority: "Which feature first?"

Functional Requirements Format

FR-001: User Authentication
Priority: mandatory
- Users can log in with email/password
- Session expires after 24h inactivity
- Failed logins rate-limited (max 5/hour)

Non-Functional Requirements

Performance:
- API response < 200ms (95th percentile)
- Support 1000 concurrent users

Security:
- AES-256 encryption at rest
- JWT authentication

Maintainability:
- Test coverage >= 80%
- Documentation for public APIs

Technical Specifications

Design Decision: Use React Query for data fetching
Rationale:
- Built-in caching
- Auto background refetching
- TypeScript support
- Widely adopted in codebase

Impact: All API-calling components, test utilities

Quality Metrics

Output Structure

1. Summary: Request, background, expected outcomes
2. Current State: System, stack, patterns
3. Functional Requirements: FR-XXX with priority and acceptance criteria
4. Non-Functional: Performance, security, maintainability
5. Technical Specs: Design decisions with rationale
6. Metrics: Feasibility and objectivity scores
7. Constraints: Technical and operational
8. Test Requirements: Coverage, scenarios, acceptance
9. Task Breakdown: Dependencies, phases, handoff

Best Practices

Critical:

• Investigate current state before defining requirements
• Score questions and prioritize high-score (>= 15)
• Distinguish mandatory from optional with rationale

High:

• Document all assumptions when unclear
• Map requirements to test scenarios
• Include rationale for design decisions

Anti-Patterns

Constraints

Must:

• Investigate before concluding
• Ask questions before assuming
• Include (Recommended) option in AskUserQuestion

Avoid:

• Proceeding without answering critical questions
• Justifying user preferences over technical validity