Documentation Criteria

1. Type System Changes

• Adding nested types with 3+ levels: type A = { b: { c: { d: T } } }
  • Rationale: Deep nesting has high complexity and wide impact scope
• Changing/deleting types used in 3+ locations
  • Rationale: Multiple location impacts require careful consideration
• Type responsibility changes (e.g., DTO->Entity)
  • Rationale: Conceptual model changes affect design philosophy

2. Data Flow Changes

• Storage location changes (DB->File, Memory->Cache)
• Processing order changes with 3+ steps
  • Example: "Input->Validation->Save" to "Input->Save->Async Validation"
• Data passing method changes (props->Context, direct reference->events)

3. Architecture Changes

• Layer addition, responsibility changes, component relocation

4. External Dependency Changes

• Library/framework/external API introduction or replacement

5. Complex Implementation Logic (Regardless of Scale)

• Managing 3+ states
• Coordinating 5+ asynchronous processes

Detailed Document Definitions

PRD (Product Requirements Document)

Purpose: Define business requirements and user value

Includes:

• Business requirements and user value
• Success metrics and KPIs (each metric specifies a numeric target, measurement method, and timeframe)
• User stories and use cases
• MoSCoW prioritization (Must/Should/Could/Won't)
• Acceptance criteria with sequential IDs (AC-001, AC-002, ...) for downstream traceability
• MVP and Future phase separation
• User journey diagram (required)
• Scope boundary diagram (required)

Scope: Business requirements, user value, success metrics, user stories, and prioritization only. Implementation details belong in Design Doc, technical selection rationale in ADR, phases and task breakdown in Work Plan.

ADR (Architecture Decision Record)

Purpose: Record technical decision rationale and background

Includes:

• Decision (what was selected)
• Rationale (why that selection was made)
• Option comparison (minimum 3 options) and trade-offs
• Architecture impact
• Principled implementation guidelines (e.g., "Use dependency injection")

Scope: Decision, rationale, option comparison, architecture impact, and principled guidelines only. Implementation procedures and code examples belong in Design Doc, schedule and resource assignments in Work Plan.

UI Specification

Purpose: Define UI structure, screen transitions, component decomposition, and interaction design for frontend features

Includes:

• Screen list and transition conditions
• Component decomposition with state x display matrix (default/loading/empty/error/partial)
• Interaction definitions linked to PRD acceptance criteria (EARS format)
• Prototype management (code-based prototypes as attachments, not source of truth)
• AC traceability from PRD to screens/components
• Existing component reuse map and design tokens
• Visual acceptance criteria (golden states, layout constraints)
• Accessibility requirements (keyboard, screen reader, contrast)

Scope: Screen structure, transitions, component decomposition, interaction design, and visual acceptance criteria only. Technical implementation and API contracts belong in Design Doc, test implementation in acceptance-test-generator skeletons, schedule in Work Plan.

Required Structural Elements:

• At least one component with state x display matrix and interaction table
• AC traceability table mapping PRD ACs to screens/states
• Screen list with transition conditions
• Existing component reuse map (reuse/extend/new decisions)

Prototype Code Handling:

• Prototype code provided by user is placed in docs/ui-spec/assets/{feature-name}/
• Prototype is an attachment to UI Spec, never the source of truth
• UI Spec + Design Doc are the canonical specifications

Design Document

Purpose: Define technical implementation methods in detail

Includes:

• Existing codebase analysis (required)
  • Implementation path mapping (both existing and new)
  • Integration point clarification (connection points with existing code even for new implementations)
• Technical implementation approach (vertical/horizontal/hybrid)
• Technical dependencies and implementation constraints (required implementation order)
• Interface and type definitions
• Data flow and component design
• Acceptance criteria (EARS format — see design-template.md; each criterion specifies a verifiable condition with pass/fail threshold)
• Change impact map (clearly specify direct impact/indirect impact/no ripple effect)
• Complete enumeration of integration points
• Data contract clarification
• Agreement checklist (agreements with stakeholders)
• Code inspection evidence (inspected files/functions during investigation)
• Field propagation map (when fields cross component boundaries)
• Data representation decision (when introducing new structures)
• Applicable standards (explicit/implicit classification)
• Prerequisite ADRs (including common ADRs)
• Verification Strategy (required)
  • Correctness proof method (what "correct" means for this change, how it's verified, when)
  • Early verification point (first target to prove the approach works, success criteria, failure response)

Scope: Technical implementation methods, interfaces, data flow, acceptance criteria, and verification strategy only. Technology selection rationale belongs in ADR, schedule and assignments in Work Plan.

Work Plan

Purpose: Implementation task management and progress tracking

Includes:

• Task breakdown and dependencies (maximum 2 levels)
• Schedule and duration estimates
• Include test skeleton file paths (integration and E2E)
• Verification Strategy summary (extracted from Design Doc)
• Final Quality Assurance Phase (required)
• Progress records (checkbox format)

Scope: Task breakdown, dependencies, schedule, verification strategy summary, and progress tracking only. Technical rationale belongs in ADR, design details in Design Doc.

Phase Division Criteria (adapt to implementation approach from Design Doc):

When Vertical Slice selected:

• Each phase = one value unit (feature, component, or migration target)
• Each phase includes its own implementation + verification per Verification Strategy

When Horizontal Slice selected:

1. Phase 1: Foundation Implementation - Type definitions, interfaces, test preparation
2. Phase 2: Core Feature Implementation - Business logic, unit tests
3. Phase 3: Integration Implementation - External connections, presentation layer

When Hybrid selected:

• Combine vertical and horizontal as defined in Design Doc implementation approach

All approaches: Final phase is always Quality Assurance (acceptance criteria achievement, all tests passing, quality checks). Each phase's verification method follows Verification Strategy from Design Doc.

Three Elements of Task Completion Definition:

1. Implementation Complete: Code is functional
2. Quality Complete: Tests, type checks, linting pass
3. Integration Complete: Verified connection with other components

Creation Process

1. Problem Analysis: Change scale assessment, ADR condition check
   • Identify explicit and implicit project standards before investigation
2. ADR Option Consideration (ADR only): Compare 3+ options, specify trade-offs
3. Creation: Use templates, include measurable conditions
4. Approval: "Accepted" after review enables implementation

Storage Locations

*Note: Work plans are excluded by .gitignore

ADR Status

Proposed -> Accepted -> Deprecated/Superseded/Rejected

AI Automation Rules

• 5+ files: Suggest ADR creation
• Type/data flow change detected: ADR mandatory
• Check existing ADRs before implementation

Diagram Requirements

Required diagrams for each document (using mermaid notation):

Common ADR Relationships

1. At creation: Identify common technical areas (logging, error handling, async processing, etc.), reference existing common ADRs
2. When missing: Consider creating necessary common ADRs
3. Design Doc: Specify common ADRs in "Prerequisite ADRs" section
4. Compliance check: Verify design aligns with common ADR decisions

Templates

Templates are available in the references/ directory:

• Design Document template
• Product Requirements Document template
• UI Specification template
• Work Plan template
• Architecture Decision Record template
• Task File template