Defect Removal Efficiency

In the recent past,IT projects are spending more time in arriving at 'defect prediction', 'defect detection', defect prevention' activities as this plays a key driver for the overall QUALITY of the product / project.

Out of this, defect removal efficiency is the one which is getting more important to the project teams as this is one of the measurement to assess the quality of the project team delivery.

The below is the formula that we normally use to calculate DRE (DefectRemoval Efficiency).

DRE =

Total Number of Defects in Dev + QA
________________________________________________ * 100
Total Number of Defects in Dev + QA + Production


This gives the % of DRE for the particular project. Different people have given different perspective on how to analyze the high quality based on the results.

But tokeep this very simple and straight forward, based on the readings of many references, I prefer going as per the below standards to arrive at the High quality measurements.

SEI-CMM Level 1 - 85%
SEI-CMM Level 2 - 89%
SEI-CMM Level 3 - 91%
SEI-CMM Level 4 - 94%
SEI-CMM Level 5 - 97%

This % may vary to some extent depending on the company / project goals. Ideally the above will be the reasonable numbers.If the software / product is being used by many clients, then we need to add one more parameter based on the client numbers.