Defect Removal Efficiency is a weighty metric used to estimate test efficacy.
With the help of Defect Removal Efficiency we can measure what quantity of software bugs we identified from the number of software bugs which we could have identified.
Here is the formula for calculating this metric:
DRE = Quantity of Bugs during Software Testing / (Quantity of Bugs during Software Testing + Quantity of Bugs found by User)
We need only 2 inputs for calculating this metric:
- Quantity of Bugs during Software Testing
- Quantity of Bugs found by User
Anyway the success of Defect Removal Efficiency depends on different aspects:
- How do we confirm when the client has identified all the defects? This is generally reached by looking at the history of the client.
- We should also take into account severity and distribution of bugs.