To compare how much time is spent troubleshooting issues discovered during development versus issues discovered after release, which KPI should you use?

The defect escape rate measures the percentage of defects found in production (after release) compared to the total number of defects found. A higher defect escape rate indicates that more issues are slipping past development and testing phases, leading to increased troubleshooting time in production. This KPI directly addresses the comparison of troubleshooting time for issues discovered during development versus after release. Unplanned work rate measures the proportion of work that was not planned, which can include troubleshooting but doesn't specifically differentiate between discovery phases. Defect rate measures the total number of defects found, but not where they were found. Rework rate measures the amount of effort spent redoing work, which is related to defects but doesn't specifically compare pre- and post-release discovery.