# Skill: Lean - Backlog Management

## Description
Manage and prioritize product backlog using WSJF (Weighted Shortest Job First) and lean principles for optimal value delivery.

## Input
- **project_id**: Project identifier (required)
- **action**: list|add|prioritize|groom|estimate (required)
- **item**: Backlog item details for add/update (optional)
- **filters**: Status, phase, assignee filters (optional)

## Backlog Item Structure
```json
{
  "id": "BLI-042",
  "title": "Add dark mode toggle",
  "description": "Allow users to switch between light and dark themes",
  "type": "feature|bug|tech_debt|spike",
  "phase": "empathize|define|ideate|prototype|test",
  "status": "idea|ready|in_progress|review|done|blocked",
  "priority_score": 8.5,
  "scoring": {
    "user_value": 7,
    "time_criticality": 3,
    "risk_reduction": 2,
    "effort": 3
  },
  "story_points": 5,
  "assigned_agent": "frontend|backend|tester|devops|pm",
  "dependencies": ["BLI-040", "BLI-041"],
  "labels": ["ux", "settings", "mvp"],
  "acceptance_criteria": [
    "Toggle visible in settings page",
    "Theme persists across sessions",
    "Respects system preference by default"
  ],
  "created_at": "2024-12-14T10:00:00Z",
  "updated_at": "2024-12-14T15:30:00Z",
  "sprint_id": null
}
```

## WSJF Prioritization

### Formula
```
Priority Score = (User Value + Time Criticality + Risk Reduction) / Effort

Scale: 1-10 for each factor
Result: Higher score = Higher priority
```

### Scoring Guide

**User Value (1-10):**
- 10: Core feature, all users need
- 7-9: Important feature, most users benefit
- 4-6: Nice to have, some users want
- 1-3: Edge case, few users affected

**Time Criticality (1-10):**
- 10: Must ship this sprint, blocking release
- 7-9: Needed soon, customer commitment
- 4-6: Planned for quarter, flexible timing
- 1-3: Backlog, no deadline

**Risk Reduction (1-10):**
- 10: Eliminates critical security/stability risk
- 7-9: Reduces significant technical debt
- 4-6: Improves maintainability
- 1-3: Minor improvement

**Effort (1-10):**
- 1-2: Trivial, < 2 hours
- 3-4: Small, 2-8 hours
- 5-6: Medium, 1-2 days
- 7-8: Large, 3-5 days
- 9-10: Epic, > 1 week (should be split)

### Priority Buckets
```
Score > 10:  🔥 Critical    - Do immediately
Score 7-10:  ⚡ High        - Sprint commitment
Score 4-7:   📌 Medium      - Plan for next sprint
Score < 4:   💤 Low         - Future backlog
```

## Backlog Actions

### List Backlog
```json
{
  "action": "list",
  "filters": {
    "status": ["ready", "in_progress"],
    "phase": "prototype",
    "label": "mvp"
  },
  "sort": "priority_score",
  "limit": 20
}
```

### Add Item
```json
{
  "action": "add",
  "item": {
    "title": "Implement password reset flow",
    "description": "Users need ability to reset forgotten passwords",
    "type": "feature",
    "phase": "prototype",
    "labels": ["auth", "mvp"],
    "acceptance_criteria": [
      "Email sent with reset link",
      "Link expires after 1 hour",
      "Password requirements enforced"
    ]
  }
}
```

### Prioritize Backlog
```json
{
  "action": "prioritize",
  "items": [
    { "id": "BLI-042", "user_value": 7, "time_criticality": 3, "risk_reduction": 2, "effort": 3 },
    { "id": "BLI-043", "user_value": 9, "time_criticality": 8, "risk_reduction": 5, "effort": 5 }
  ]
}
```

### Groom Items
```json
{
  "action": "groom",
  "item_id": "BLI-042",
  "updates": {
    "description": "Updated description with more detail",
    "acceptance_criteria": ["New criteria"],
    "story_points": 8,
    "status": "ready"
  }
}
```

## Output Format
```json
{
  "status": "success",
  "action": "list",
  "backlog": {
    "total_items": 45,
    "ready_items": 12,
    "in_progress": 5,
    "blocked": 1
  },
  "items": [
    {
      "id": "BLI-043",
      "title": "User authentication",
      "priority_score": 7.33,
      "status": "ready",
      "story_points": 8,
      "phase": "prototype"
    }
  ],
  "recommendations": [
    {
      "type": "split",
      "item_id": "BLI-050",
      "reason": "Effort score 9 - consider breaking into smaller items"
    },
    {
      "type": "prioritize",
      "item_id": "BLI-043",
      "reason": "High time criticality, move to top"
    }
  ],
  "next_step": "Plan sprint with /sprint plan"
}
```

## AI Advisory

### Recommendations Engine
```javascript
function generateRecommendations(backlog) {
  const recommendations = [];

  // Large items should be split
  backlog.filter(i => i.scoring.effort >= 8).forEach(item => {
    recommendations.push({
      type: 'split',
      item_id: item.id,
      reason: `Effort ${item.scoring.effort} is too high. Split into 2-3 smaller items.`,
      priority: 'high'
    });
  });

  // Blocked items need attention
  backlog.filter(i => i.status === 'blocked').forEach(item => {
    recommendations.push({
      type: 'unblock',
      item_id: item.id,
      reason: `Item blocked. Check dependencies: ${item.dependencies.join(', ')}`,
      priority: 'critical'
    });
  });

  // Old items in "idea" status
  const oldIdeas = backlog.filter(i =>
    i.status === 'idea' &&
    daysSince(i.created_at) > 30
  );
  if (oldIdeas.length > 5) {
    recommendations.push({
      type: 'cleanup',
      reason: `${oldIdeas.length} items in "idea" status for 30+ days. Review or remove.`,
      priority: 'medium'
    });
  }

  return recommendations;
}
```

## Quality Gates
- [ ] All items have clear titles
- [ ] Ready items have acceptance criteria
- [ ] WSJF scores calculated
- [ ] Dependencies documented
- [ ] Large items flagged for splitting
- [ ] Blocked items have resolution plan

## Token Budget
- Max input: 800 tokens
- Max output: 1500 tokens

## Model
- Recommended: sonnet (prioritization reasoning)

## Philosophy
> "Build less, ship faster. Priority is about saying no."

**Keep it simple:**
- Small items > Large epics
- Done > Perfect
- User value > Technical elegance
- Weekly grooming beats quarterly planning