majiayu000 pm-user-stories — Break an Epic into User Stories
Part of the Personal Corp framework — running a one-person business through AI agents. Decompose a large requirement or Epic into independently-deliverable User Stories. Every Story is validated against INVEST. Output is ready to paste into Jira, Linear, or GitHub Issues.
Inputs
| Field | Required | Notes |
|---|---|---|
| Requirement description | yes | An Epic or large requirement; can paste a PRD section |
| Granularity | no | Sprint-level (1-3 days/story) or iteration-level (1-2 weeks); default Sprint |
| Team composition | no | FE+BE split / full-stack / has mobile — affects per-tier splitting |
| Estimation system | no | Fibonacci (1/2/3/5/8/13) or T-shirt (S/M/L/XL); default Fibonacci |
Step 1 — Map the full requirement
Extract from the requirement:
- Roles involved: who uses this? (end user, admin, ops, etc.)
- Core flow: main path? branches?
- Business rules: constraints and conditions?
- Data entities: what data objects are involved?
Step 2 — Pick a splitting pattern
Five patterns. Pick by requirement shape; combine for hybrids.
| Pattern | When to use | Example |
|---|---|---|
| By workflow step | Requirement is a complete process | Checkout → pick item / address / payment / confirm |
| By business-rule variant | Same feature with multiple rule sets | Discount → fixed-amount / coupon / points / combined |
| By CRUD operation | Requirement centers on one data object | Address book → create / edit / delete / set default |
| By role perspective | Multi-role feature | Order management → user view / merchant processing / ops dashboard |
| By complexity progression | Feature has simple and full versions | Search → keyword / filters / suggestions / history |
Selection principle: target ≤ 1 Sprint per Story. Hybrid requirements combine patterns.
Granularity calibration:
- Stories < 3 → likely too coarse; check for hidden sub-flows
- Stories > 20 → likely too fine, or this is multiple Epics; split Epics first
- Single Story estimate > 8 points → too big; split further
Step 3 — Write each User Story + AC
### US-{N}: {Story title — verb-led, e.g. "Choose payment method"}
**Role:** As a {role}
**Action:** I want to {specific action}
**Value:** so that {business value}
**Priority:** P0 (must) / P1 (important) / P2 (nice-to-have)
**Story Points:** {estimate}
**Acceptance Criteria:**
- [ ] Given {precondition}, When {action}, Then {expected result}
- [ ] Given {exception precondition}, When {action}, Then {error handling}
**Dependencies:** {other Story IDs, or "none"}
**Tech notes:** {dev callouts, optional}
Story Point reference (Fibonacci):
| Points | Complexity | Effort | Typical scope |
|---|---|---|---|
| 1 | Trivial | < 0.5 day | Copy change, config tweak, add an event |
| 2 | Simple | 0.5-1 day | One CRUD operation, form validation |
| 3 | Medium | 1-2 days | A complete feature point with business logic |
| 5 | Complex | 2-4 days | Multi-module interaction |
| 8 | Big | 4-7 days | New system / new flow core module |
| 13 | Re-split | > 1 week | Means the Story is too big — must split |
AC quality rules — every AC must satisfy:
- Specific: Given clause has a concrete precondition ("user logged in AND balance ≥ 100"), not "user logged in"
- Testable: Then clause has a verifiable result ("balance decreases by 100 AND order status = paid"), not "payment succeeds"
- Edge coverage: every Story has ≥ 1 happy-path AC + ≥ 1 exception-path AC
Step 4 — INVEST validation
Run each Story against the six checks:
| Principle | Check | If fails |
|---|---|---|
| Independent | Delete this Story — can the others still ship? | Cyclic deps → merge or re-split |
| Negotiable | Does it describe "what" or "how"? | Strip implementation detail, keep value |
| Valuable | Will the user perceive value when this ships? | Pure refactor → attach to a user-perceivable feature |
| Estimable | Can the team agree on points within 5 minutes? | Wide spread = unclear requirement; clarify first |
| Small | Fits in one Sprint? | Larger → split |
| Testable | Can QA write test cases directly from the AC? | Add concrete edge values and expected results |
Definition of Ready (must hold before entering development):
| Check | Standard | If unmet |
|---|---|---|
| AC complete | ≥ 1 happy + ≥ 1 exception | Fill ACs, then schedule |
| No blocking deps | All upstream Stories done or mockable | Tag "Blocked", push to a later Sprint |
| Designs ready | UI Stories have design specs | No designs → tag "Needs design" |
| Estimation consensus | Spread < 2× | Re-discuss scope until agreed |
| Business rules confirmed | All [TBD] resolved |
Confirm with PM/business, then dev |
Dependency rules:
- Data dependency: Story B needs data created by Story A → B depends on A
- Interface dependency: Story B calls API provided by A → B depends on A
- No dependency: Stories on different objects or different roles → parallel
- Pseudo-dependency: looks dependent but mockable → tag "Mockable to decouple"
Step 5 — Output a Story Map
## Epic: {requirement name}
### Story Map (user journey → Story mapping)
| Journey stage | Stories | Priority | Points |
|---|---|---|---|
| {stage 1} | US-001, US-002 | P0 | 5 |
| {stage 2} | US-003, US-004 | P1 | 8 |
### Sprint planning
- **Sprint 1 (MVP):** {Story list}, total {X} points
- **Sprint 2:** {Story list}, total {X} points
### Dependencies
US-001 → US-003 → US-005 (must follow this order)
US-002, US-004 (parallel)
Quality bar
- Every Story passes all six INVEST checks
- AC uses Given-When-Then with ≥ 1 happy + ≥ 1 exception
- Dependencies tagged explicitly, with mockability flagged
- 13-point Stories must be re-split
- Story Map includes Sprint planning suggestion
When input is incomplete
- One-sentence requirement → first output a feature outline, confirm scope, then split
- Too large (> 20 Stories) → recommend splitting into Epics; agree on MVP scope first
- Missing business rules → tag
[business rule TBD]and propose plausible assumptions for confirmation
Related skills
/pm-prd— write a PRD first to lock scope, then break into Stories/pm-prioritize— when there are many Stories, RICE-rank for Sprint priority