Breakdown Epic Skill

Purpose

Transform high-level epics or features into detailed, actionable user stories ready for sprint planning and implementation.

Core Capabilities:

Epic scope analysis and component identification
User story creation (As a... I want... So that...)
Story point estimation (complexity/effort/risk)
Dependency mapping between stories
Sprint grouping suggestions
Story and epic file generation

Prerequisites

Configuration file (.claude/config.yaml) with planning settings
Epic description (20+ words minimum)
Story point scale defined (default: Fibonacci 1,2,3,5,8,13,21)

Workflow

Step 0: Load Configuration and Epic Description

Action: Load configuration and parse epic requirements.

Load config: Read .claude/config.yaml for planning settings (storiesLocation, epicsLocation, defaultVelocity, storyPointScale, techStack)

Get epic description: From user input (20+ words minimum), parse scope, business goals, technical requirements

Prepare directories: Create stories and epics directories

See: references/templates.md#configuration-format and #step-0-configuration-loading for details

Halt if:

Configuration missing
Epic description <20 words (too vague)
Cannot create directories

See: references/epic-analysis-guide.md for scope analysis

Step 1: Analyze Epic Scope

Action: Break down epic into major components and sub-features.

Identify components:

Core Features - What functionality is needed?
User Types - Who will use this?
Technical Requirements - What tech/integrations?
Security Requirements - What needs protection?
Non-Functional Requirements - Performance, scalability, etc.

Output: Epic analysis with major components, sub-features, user types, technical/security requirements, NFRs

See: references/templates.md#step-1-epic-analysis-example for complete analysis format

Group by themes:

Related features together
Similar technical complexity
Common user journeys

See: references/epic-analysis-guide.md for detailed analysis techniques

Step 2: Create User Stories

Action: Convert components into user stories with acceptance criteria.

Story format: "As a [user], I want [capability], So that [benefit]" with acceptance criteria, priority, component

See: references/templates.md#step-2-user-story-format for format and 5 complete examples

Story quality checks:

Clear user perspective
Specific, testable acceptance criteria (2-5 per story)
Appropriate priority
Properly scoped (not too large, not too small)

See: references/story-creation-guide.md for story writing best practices

Step 3: Estimate Story Points

Action: Estimate each story using complexity, effort, and risk.

Estimation factors: Complexity (1-5), Effort (1-5), Risk (1-3)

Calculate: Story Points = Complexity + Effort + Risk, round to Fibonacci (1, 2, 3, 5, 8, 13, 21)

See: references/templates.md#step-3-estimation-factors-template for detailed scales and examples

See: references/estimation-guide.md for detailed estimation techniques

Step 4: Identify Dependencies

Action: Map dependencies between stories.

Dependency types:

1. Blocks: Story A must complete before Story B can start

story-auth-001 (Signup) BLOCKS story-auth-003 (Email Verification)

2. Related: Stories share components but can be done in parallel

story-auth-001 (Signup) RELATED story-auth-002 (Login)

Dependency rules:

Foundation before features (models before APIs)
Authentication before authorization
Core functionality before enhancements
Infrastructure before applications

Output: Dependency graph with BLOCKS/REQUIRES/RELATED relationships, critical path identification

See: references/templates.md#step-4-dependency-examples for complete graph format

See: references/dependency-mapping-guide.md for dependency analysis

Step 5: Suggest Sprint Groupings

Action: Group stories into sprints based on dependencies, priorities, and velocity.

Grouping rules:

Priority first - P0 stories in early sprints
Dependencies respected - Blocked stories after blockers
Velocity constraints - Don't exceed team capacity
Logical grouping - Related stories together

Output: Sprint groupings with story assignments, velocity constraints, dependency respect, logical grouping

See: references/templates.md#step-5-sprint-grouping-example for complete sprint plan format

Step 6: Generate Story Files and Epic Summary

Action: Create story markdown files and epic summary.

Generate files: Use bmad-commands write_file for each story and epic summary

Output: Story files (complete format with user story, ACs, dependencies, estimation, DoD) and epic summary file

See: references/templates.md#step-6-story-file-format-template and #step-6-epic-summary-file-format for complete structures

Step 7: Present Summary to User

Action: Present epic breakdown summary for review.

Output: Breakdown complete summary with story count, points, sprints, files, priorities, sprint plan, dependencies

See: references/templates.md#step-7-summary-output-template for complete format

Output

Return structured JSON with story_files, epic_file, metrics (total_points, story_count, sprint_count), and telemetry

See: references/templates.md#json-output-format for complete structure

Best Practices

Epic Scope - Keep epics focused (10-15 stories max)
Story Size - Target 3-8 points per story (not too large)
Clear ACs - 2-5 specific, testable acceptance criteria
Priority Discipline - Not everything can be P0
Dependency Mapping - Identify blockers early
Velocity Reality - Don't overcommit sprint capacity

See: references/story-creation-guide.md for best practices

Routing Guidance

Use this skill when:

Starting new epic or major feature
During backlog grooming sessions
Planning multiple sprints ahead
Breaking down product requirements

Always use before:

sprint-plan skill (sprint planning)
refine-story skill (detailed story refinement)

Feeds into:

create-task-spec skill (for implementation specs)

Reference Files

Detailed documentation in references/:

templates.md: All output formats, config examples, story/epic file templates
epic-analysis-guide.md: Epic scope analysis, component identification
story-creation-guide.md: User story format, acceptance criteria, best practices
estimation-guide.md: Story point estimation techniques
dependency-mapping-guide.md: Dependency types, mapping, sprint grouping

Part of BMAD Enhanced Planning Suite

breakdown-epic