DRE or defect removal efficiency gives a measure of the development team ability to remove defects prior to release. It is calculated as a ratio of defects resolved to total number of defects found. It is typically measured prior and at the moment of release.
How to Calculate
To be able to calculate that metric, it is important that in your defect tracking system you track: affected version, version of software in which this defect was found, release date and date when version was released
DRE = Number of defects resolved by the development team / total number of defects at the moment of measurement.
