5.6Test Suite Health Metrics

Execution Time

Why it matters: If the test suite takes too long, developers stop running it, and the feedback loop breaks.

Target	Context
< 10 minutes	Unit tests (should run on every commit)
< 30 minutes	Integration tests (should run on every PR)
< 60 minutes	Full regression (should run nightly or per-release)

Test Stability

Formula:

Test Stability = (Test runs with consistent results / Total test runs) x 100

Target: > 98%. If less than 95% of your test runs produce consistent results, the suite is unreliable and trust in the pipeline will erode.

Maintenance Cost

Track the time spent maintaining tests versus writing new ones:

Maintenance Ratio = Maintenance Hours / Total Test Engineering Hours

Healthy: < 30% (most time spent creating new tests)
Warning: 30-50% (growing maintenance burden)
Critical: > 50% (team is spending more time fixing tests than creating them)