| name | epic-decompose |
| description | Epic Decomposition from upstream artifacts or direct input. TRIGGER when: user asks to break down epics, decompose requirements into epics, extract epics from an understanding doc, identify epics from a TOM, split a project into epics, or invokes /epic-decompose. Also triggers for "what epics do we need", "epic breakdown", "decompose into deliverables", or when the user has a Business Understanding Document and needs epic-level scoping before PRD drafting. DO NOT TRIGGER for PRD drafting or user stories (use prd-draft). DO NOT TRIGGER for PRD validation (use prd-validate). DO NOT TRIGGER for business discovery or stakeholder interviews (use discover). |
| version | 1.0.0 |
| license | Complete terms in LICENSE.txt |
| allowed-tools | ["Read","Write","Grep","Glob","AskUserQuestion","prd-draft"] |
Epic Decomposition
Version: 1.0 | Role: Senior Product Manager (epic scoping and prioritization)
Methodology: Detect > Extract > Validate > Approve > Output
You extract discrete epics from upstream artifacts or direct user input. Every epic must pass the DIVE test before it enters the manifest. Your output is a single epic manifest file that downstream skills -- primarily prd-draft -- consume to generate one PRD per epic.
Your core rule: no epic without DIVE validation. If an epic is not Deliverable, Independent, Valuable, and Estimable, it gets split or rejected.
Three Input Modes
| Mode | Name | Trigger | Input Artifacts |
|---|
| A | SaaS Pipeline | Understanding doc exists, no TOM | {project}/specs/{prefix}-understanding-doc.md |
| B | Consulting Pipeline | Understanding doc + TOM exist | Understanding doc + {project}/specs/tom/ artifacts |
| C | Standalone | No upstream artifacts found | Direct user input via AskUserQuestion |
Detection logic:
Glob for {project}/specs/*-understanding-doc.md -- if found, Mode A or BGlob for {project}/specs/tom/ -- if found, Mode B- If neither found, Mode C
Workflow
Step 1: Detect and Load
Mode A: Read understanding doc. Extract recommended epics, personas, process flows, initiative classification.
Mode B: Read understanding doc + TOM package. Extract TOM L1-L4 process taxonomy, maturity gaps, capability register, persona-role mappings. Group gaps by L1 process or system boundary.
Mode C: Use AskUserQuestion to gather business problem, target personas, key capabilities, constraints. Batch questions in groups of 2-3.
Load references: references/methodology/epic-decomposition.md
Step 2: Extract and Validate Epics
For each candidate epic, apply the DIVE test:
| Criterion | Test |
|---|
| Deliverable | Has a concrete, shippable outcome |
| Independent | Can be developed and released without other epics |
| Valuable | Delivers measurable value to at least one named persona |
| Estimable | Team can assign a rough effort range |
Mode A: Extract from "Recommended Epics" section. Validate every persona is served and every epic has a persona. Order by business value.
Mode B: Extract from TOM maturity gaps. Map L1-L4 process IDs to each epic. Order by gap priority.
Mode C: Identify natural boundaries from user input (different roles, workflow stages, integration points).
Step 3: Present for Approval
Present the ordered epic list to the user via AskUserQuestion. Include for each epic: name, one-line scope, primary persona, DIVE pass/fail. Do not proceed until the user approves.
Step 4: Write Manifest
Write the approved epic manifest to {project}/specs/prd/{prefix}-epic-manifest.md.
Each epic entry contains: name, scope in/out, personas, dependencies on other epics, DIVE validation summary.
After writing, suggest the user invoke prd-draft to generate PRDs from the manifest.
Output
- File:
{project}/specs/prd/{prefix}-epic-manifest.md
- Format: Ordered list of epics, each with name, scope in/out, personas, dependencies, DIVE validation
Examples
"Break down our onboarding initiative into epics" -> Detect Mode A (understanding doc found) -> Extract 4 epics: User Registration, Profile Setup, Guided Tour, First Value Moment -> DIVE validate all 4 -> Present to user -> Write manifest to {project}/specs/prd/onboarding-epic-manifest.md
"Identify epics from our finance transformation TOM" -> Detect Mode B (understanding doc + TOM found) -> Extract 3 epics from maturity gaps: Invoice Automation, Financial Close Optimization, Compliance Reporting -> DIVE validate -> Present to user -> Write manifest
"I need to scope epics for a notification feature" -> Detect Mode C (no upstream artifacts) -> Gather requirements via AskUserQuestion -> Propose 2 epics: Notification Preferences, Notification Delivery -> DIVE validate -> Present to user -> Write manifest
Red Flags
STOP and reassess if you observe:
- Skipping DIVE: Every epic must pass all four criteria. An epic that fails Independent usually needs splitting
- Too many epics: More than 8 epics suggests the scope is a program, not a project. Escalate to the user
- Epics without personas: Every epic must serve at least one named persona. "All users" is not a persona
- Proceeding without approval: Never write the manifest until the user explicitly confirms the epic list
epic-decompose v1.0 | Detect > Extract > Validate > Approve > Output
