Defect Escape Rate
It is not uncommon to identify bugs and issues after software is deployed in production. These bugs are considered to have “escaped” the previous testing efforts.
The defect escape rate metric is used to identify the rate of issues identified after a software program is in production, referred to as the defect escape rate. A higher defect escape rate is an indication that there is an issue with the testing processes or the automated testing tools being used. A lower defect escape rate (preferably close to zero) indicates that the software is of high quality and that testing processes and tools being used are functioning as expected.
The defect escape rate is measured during the Operate phase.
This metric’s measurement can be based on specific time cycles. For example, the number of defects identified in each release can be measured monthly and then translated to the value for identifying the average number of defect escapes per release. The rate per period of time, per release or per deployment can then be calculated.