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

// 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

{
  "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

// 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

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 - Agent coordination
• cicd-pipeline-qe-orchestrator - Quality gates
• risk-based-testing - Risk-informed metrics
• 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.