---
name: lean
description: Lean Software Development analysis — defines MVP scope for new projects or analyzes improvement opportunities for existing ones. Runs BEFORE IPA stages. Use when starting a new idea that needs MVP definition and scope validation, when analyzing a feature improvement against an existing system, or when eliminating waste before committing to full IPA documentation. Trigger phrases: "lean analysis", "define mvp", "lean feature analysis".
---

## Flags

- `--fast`: Skip GATE 1 prompt (not recommended for new projects)

## Overview

Lean Software Development analyst combining Product Owner vision with Data Analyst rigor. Automatically detects context: MVP definition mode (no docs) or feature improvement mode (docs exist).

## When to Use

- Starting a new project idea that needs MVP scoping
- Analyzing a feature improvement against an existing system
- Validating scope before committing to IPA documentation
- Eliminating waste and surfacing assumptions before building

## Don't Use When

- IPA docs already exist and you are ready to implement (go straight to plan)
- Design or detail work is already complete

## Mode Detection

1. **No docs exist** → MVP Definition Mode
   - Define core problem
   - Identify MVP features
   - List assumptions to validate

2. **docs/SRD.md exists** → Feature Improvement Mode
   - Read existing system docs
   - Analyze current state
   - Suggest specific improvements

## Core Principles (Lean Software Development)

| Principle | Application |
|-----------|-------------|
| Eliminate Waste | Only features with clear user value |
| Amplify Learning | Validate assumptions early |
| Decide Late | Keep options open until necessary |
| Deliver Fast | Smallest valuable increment first |
| Build Integrity In | Quality from start |
| See The Whole | Consider full user journey |

## Workflow

### Phase 1: Context Understanding

Check for existing docs (SRD.md, API_SPEC.md, UI_SPEC.md). Read if present; proceed with MVP definition if absent.

### Phase 2: Discovery

Clarify with user:
- Who is the target user?
- What problem are we solving?
- What does success look like?
- What constraints exist?

### Phase 3: Analysis

MVP Mode: define core problem, minimum features, assumptions, explicit out-of-scope items.

Feature Mode: analyze current capabilities, improvement opportunities, impact vs effort, prioritized changes.

### Phase 4: Research (if needed)

Search for market/competitor analysis, technical feasibility, external package research, mockup analysis.

### Phase 5: Explore Alternatives

For significant decisions, present 2-3 viable approaches with pros/cons and a recommendation.

### Phase 6: Output

Generate structured output ready for ipa-spec or plan.

## Output Format

### MVP Mode

```markdown
# Lean MVP Analysis: [Project Name]

## Problem Statement
## Target Users
| User Type | Description | Primary Need |

## MVP Features (→ FR-xx)
| Priority | Feature | User Value | Screen | Assumption |

## Implementation Phases
| Phase | Focus | Key Features | Effort |

## GATE 1: Scope Validation
- [ ] Talked to 3+ potential users
- [ ] Users confirmed real pain point
- [ ] MVP scope ≤ 3 phases
- [ ] Assumptions documented
- [ ] Team aligned on priorities

## MVP Screens (→ S-xx)
## Data Entities (→ E-xx)
## User Flow (→ Screen Flow)
## Tech Decisions (→ D-xx)
## Nice-to-Have (Post-MVP)
## Key Assumptions to Validate
## Out of Scope
## Risks
```

### Feature Improvement Mode

```markdown
# Lean Feature Analysis: [Feature Name]

## Current State
## Problem/Opportunity
## Proposed Changes
| Change | User Value | Effort | Priority |

## Impact Analysis
- Affected screens: [S-xx]
- Affected APIs: [endpoints]
- Affected entities: [E-xx]

## Assumptions
## Recommendation
## Next Step
```

## Save Report

Save report to: `plans/reports/lean-{date}-{slug}.md`

## Critical Rules

1. Focus on VALUE — every feature must have clear user value
2. Challenge assumptions — question what user thinks they need
3. Keep it small — MVP means MINIMUM viable
4. Validate first — identify riskiest assumptions
5. No implementation — only analysis and requirements

## Integration

```
lean [idea]
    ↓
MVP/Feature Requirements
    ↓
ipa-spec → SRD.md + UI_SPEC.md
    ↓
ipa-design → HTML mockups
    ↓
ipa-detail → API_SPEC.md, DB_DESIGN.md
    ↓
plan → Implementation tasks
```