Quality Metrics

by proffesor-for-testing

skill

Measure quality effectively with actionable metrics. Use when establishing quality dashboards, defining KPIs, or evaluating test effectiveness.

Skill Details

Repository Files

4 files in this skill directory


name: quality-metrics description: "Measure quality effectively with actionable metrics. Use when establishing quality dashboards, defining KPIs, or evaluating test effectiveness." category: testing-methodologies priority: high tokenEstimate: 900 agents: [qe-quality-analyzer, qe-test-executor, qe-coverage-analyzer, qe-production-intelligence, qe-quality-gate] implementation_status: optimized optimization_version: 1.0 last_optimized: 2025-12-02 dependencies: [] quick_reference_card: true tags: [metrics, dora, quality-gates, dashboards, kpis, measurement]

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


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.

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Skill Information

Category:Skill
Last Updated:12/3/2025