Defect metrics

// 6 metrics · updated may 2026

Metrics that track what defects you ship, find, and fix. Each metric has a working calculator and benchmarks from Capers Jones, DORA, and World Quality Report data.

Showing 6 of 6 metrics

Defect density= defects ÷ KLOC

The number of confirmed defects per thousand lines of code — the headline measure of code quality for a release.

benchmark
Defect escape rate= production defects ÷ total defects × 100%

The percentage of defects not caught before release — the most direct measure of testing effectiveness.

benchmark
Mean time to detect (MTTD)= avg(detection time − introduction time)

The average time between when a defect is introduced and when it is detected — a direct measure of feedback loop speed.

benchmark
Mean time to repair (MTTR)= avg(deploy-fix time − detection time)

The average time from defect detection to deployed fix — a measure of how quickly your team resolves confirmed issues.

benchmark
Defect severity distribution= count per severity ÷ total

How your defects break down by severity level — the signal that distinguishes a manageable bug queue from a crisis.

qualitative
Defect removal efficiency (DRE)= defects found pre-release ÷ total defects × 100%

The percentage of total defects found before release — the inverse of defect escape rate and a measure of testing thoroughness.

benchmark

// Continue exploring

Test metrics

Coverage, automation ratio, pass rate, flakiness, execution time, requirements traceability.

7 metrics

Process metrics

DORA metrics (deploy frequency, lead time, change failure, MTTR), cycle time.

5 metrics