Regression Debt Ratio

Regression Debt Ratio is the relationship between the size of an automated test suite and the monthly hours an agency spends keeping it green. Every recorded flow, visual diff, or coverage target adds a small permanent tax: selector updates, environment drift, flaky reruns. The framework asks agencies to measure that tax against the delivery hours it saves before adding another test. A useful illustration sits in the tooling itself: Supercov feeds uncovered code paths to coding agents so they write targeted tests, which grows suites quickly, while config-drift-checker exists precisely because agent setups decay as models and versions move. Agencies running fixed-bid retainers feel this first, since unbilled maintenance hours come straight out of margin. The discipline is to cap suite growth per client, retire tests that never catch anything, and price QA-as-a-service with maintenance included rather than absorbed.