What Is Defect Ratio Testing

Definition : The defect detection percentage (DDP) gives a measure of the testing effectiveness. It is calculated as a ratio of defects found found prior to release and after release by customers.

What is a defect ratio?

The formula for defect rate is the amount of defective products observed divided by the number of units tested. For example, if 10 out of 200 tested units are defective, the defect rate is 10 divided by 200, or 5 percent. Defect rate is often stated in terms of defects per million.

How is defect percentage calculated in testing?

One of the metrics which measures the quality of your company’s testing is the Defect Detection Percentage. The formula is simple, tally the number of defects found during testing, then divide that number by the number of total defects and there’s your Defect Detection Percentage!