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)

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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

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Step 1: Analyze Epic Scope

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

Identify components:

1. Core Features - What functionality is needed?
2. User Types - Who will use this?
3. Technical Requirements - What tech/integrations?
4. Security Requirements - What needs protection?
5. 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

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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

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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

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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

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Step 5: Suggest Sprint Groupings

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

Grouping rules:

1. Priority first - P0 stories in early sprints
2. Dependencies respected - Blocked stories after blockers
3. Velocity constraints - Don't exceed team capacity
4. 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

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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

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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

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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

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Best Practices

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

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

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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)

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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

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Part of BMAD Enhanced Planning Suite