quality-metrics

# Quality Metrics

<default_to_action>
When measuring quality or building dashboards:
1. MEASURE outcomes (bug escape rate, MTTD) not activities (test count)
2. FOCUS on DORA metrics: Deployment frequency, Lead time, MTTD, MTTR, Change failure rate
3. AVOID vanity metrics: 100% coverage means nothing if tests don't catch bugs
4. SET thresholds that drive behavior (quality gates block bad code)
5. TREND over time: Direction matters more than absolute numbers

**Quick Metric Selection:**
- Speed: Deployment frequency, lead time for changes
- Stability: Change failure rate, MTTR
- Quality: Bug escape rate, defect density, test effectiveness
- Process: Code review time, flaky test rate

**Critical Success Factors:**
- Metrics without action are theater
- What you measure is what you optimize
- Trends matter more than snapshots
</default_to_action>

## Quick Reference Card

### When to Use
- Building quality dashboards
- Defining quality gates
- Evaluating testing effectiveness
- Justifying quality investments

### Meaningful vs Vanity Metrics
| ✅ Meaningful | ❌ Vanity |
|--------------|-----------|
| Bug escape rate | Test case count |
| MTTD (detection) | Lines of test code |
| MTTR (recovery) | Test executions |
| Change failure rate | Coverage % (alone) |
| Lead time for changes | Requirements traced |

### DORA Metrics
| Metric | Elite | High | Medium | Low |
|--------|-------|------|--------|-----|
| Deploy Frequency | On-demand | Weekly | Monthly | Yearly |
| Lead Time | < 1 hour | < 1 week | < 1 month | > 6 months |
| Change Failure Rate | < 5% | < 15% | < 30% | > 45% |
| MTTR | < 1 hour | < 1 day | < 1 week | > 1 month |

### Quality Gate Thresholds
| Metric | Blocking Threshold | Warning |
|--------|-------------------|---------|
| Test pass rate | 100% | - |
| Critical coverage | > 80% | > 70% |
| Security critical | 0 | - |
| Performance p95 | < 200ms | < 500ms |
| Flaky tests | < 2% | < 5% |

---

## Core Metrics

### Bug Escape Rate
```
Bug Escape Rate = (Production Bugs / Total Bugs Found) × 100

Target: < 10% (90% caught before production)
```

### Test Effectiveness
```
Test Effectiveness = (Bugs Found by Tests / Total Bugs) × 100

Target: > 70%
```

### Defect Density
```
Defect Density = Defects / KLOC

Good: < 1 defect per KLOC
```

### Mean Time to Detect (MTTD)
```
MTTD = Time(Bug Reported) - Time(Bug Introduced)

Target: < 1 day for critical, < 1 week for others
```

---

## Dashboard Design

```typescript
// Agent generates quality dashboard
await Task("Generate Dashboard", {
  metrics: {
    delivery: ['deployment-frequency', 'lead-time', 'change-failure-rate'],
    quality: ['bug-escape-rate', 'test-effectiveness', 'defect-density'],
    stability: ['mttd', 'mttr', 'availability'],
    process: ['code-review-time', 'flaky-test-rate', 'coverage-trend']
  },
  visualization: 'grafana',
  alerts: {
    critical: { bug_escape_rate: '>20%', mttr: '>24h' },
    warning: { coverage: '<70%', flaky_rate: '>5%' }
  }
}, "qe-quality-analyzer");
```

---

## Quality Gate Configuration

```json
{
  "qualityGates": {
    "commit": {
      "coverage": { "min": 80, "blocking": true },
      "lint": { "errors": 0, "blocking": true }
    },
    "pr": {
      "tests": { "pass": "100%", "blocking": true },
      "security": { "critical": 0, "blocking": true },
      "coverage_delta": { "min": 0, "blocking": false }
    },
    "release": {
      "e2e": { "pass": "100%", "blocking": true },
      "performance_p95": { "max_ms": 200, "blocking": true },
      "bug_escape_rate": { "max": "10%", "blocking": false }
    }
  }
}
```

---

## Agent-Assisted Metrics

```typescript
// Calculate quality trends
await Task("Quality Trend Analysis", {
  timeframe: '90d',
  metrics: ['bug-escape-rate', 'mttd', 'test-effectiveness'],
  compare: 'previous-90d',
  predictNext: '30d'
}, "qe-quality-analyzer");

// Evaluate quality gate
await Task("Quality Gate Evaluation", {
  buildId: 'build-123',
  environment: 'staging',
  metrics: currentMetrics,
  policy: qualityPolicy
}, "qe-quality-gate");
```

---

## Agent Coordination Hints

### Memory Namespace
```
aqe/quality-metrics/
├── dashboards/*         - Dashboard configurations
├── trends/*             - Historical metric data
├── gates/*              - Gate evaluation results
└── alerts/*             - Triggered alerts
```

### Fleet Coordination
```typescript
const metricsFleet = await FleetManager.coordinate({
  strategy: 'quality-metrics',
  agents: [
    'qe-quality-analyzer',         // Trend analysis
    'qe-test-executor',            // Test metrics
    'qe-coverage-analyzer',        // Coverage data
    'qe-production-intelligence',  // Production metrics
    'qe-quality-gate'              // Gate decisions
  ],
  topology: 'mesh'
});
```

---

## Common Traps

| Trap | Problem | Solution |
|------|---------|----------|
| Coverage worship | 100% coverage, bugs still escape | Measure bug escape rate instead |
| Test count focus | Many tests, slow feedback | Measure execution time |
| Activity metrics | Busy work, no outcomes | Measure outcomes (MTTD, MTTR) |
| Point-in-time | Snapshot without context | Track trends over time |

---

## Related Skills
- [agentic-quality-engineering](../agentic-quality-engineering/) - Agent coordination
- [cicd-pipeline-qe-orchestrator](../cicd-pipeline-qe-orchestrator/) - Quality gates
- [risk-based-testing](../risk-based-testing/) - Risk-informed metrics
- [shift-right-testing](../shift-right-testing/) - Production metrics

---

## Remember

**Measure outcomes, not activities.** Bug escape rate > test count. MTTD/MTTR > coverage %. Trends > snapshots. Set gates that block bad code. What you measure is what you optimize.

**With Agents:** Agents track metrics automatically, analyze trends, trigger alerts, and make gate decisions. Use agents to maintain continuous quality visibility.