Defect Removal Efficiency %(DRE%) Phase-wise

What is DRE and what do we conclude from DRE?

Definition:

DRE % indicates the effective identification and removal of defects both at phase-level and project-level

Conclusion from DRE %:

• If Over-all Project DRE is between 90%-100%, then the efficiency is said to be at High level.
• If Over-all Project DRE is between 75%-90%, then the efficiency is said to be at Moderate level.
• If Over-all Project DRE is below 75%, then the efficiency is said to be at Alarming level.

Defects Removed during a Phase 

DRE % = ------------------------------------------- X 100 

Defects Removed till date

DRE % @ Requirement Phase = 10/(10+3+0+2+1) x 100 = 62.50 %

DRE % @ Design Phase = (3+18)/(3+0+2+1+18+4+5+2) x100 = 60.00 %

DRE % @ Coding Phase =(0+4+26)/(0+2+1+4+5+2+26+8+7) x100 = 54.54 %

DRE % @ Testing Phase =(2+5+8)/(2+1+5+2+8+7) x 100 = 60.00 %

Note: Here the total defects of one phase are carried over to next phase also.

What is the reason to carry over the bugs of one phase to another?
Ans:
For example: There is some defects found in design phase, which are pertaining to Requirements. Typically these bugs should be removed during requirements phase itself. But since the bugs were not removed in requirement phase and is observed as bug pertaining to requirement phase during design phase, the bugs will be considered as count for both requirements and design phase.

Defect Removal Efficiency %(DRE%) for the project 

Total No. Of Defects before Release/Delivery 

DRE % = ------------------------------------------------------ X 100 

Total No. Of Defects for the Project 

For the above mentioned example, 

(10+3+2+18+4+5+26+8) 

Over-all DRE % = ---------------------------------------- x 100 = 88.37 % 

(10+3+2+1+18+4+5+2+26+8+7)