The most commonly used inspection metrics are

Total number of defects = A+ B – C

Where A and B are the total number of defects detected by reviewer 1 and reviewer 2 while C is the total number of common defects detected by both reviewers

Defect density is the ratio of the number of defects found to the size of the artefact

Defect Density = Total defects found / Size

Estimated Total Number of Defects is the sum of the total number of defects found and the estimated total number of defects remaining.

Capture recapture approach detects total number of defects.

Estimated Total Number of Defects = A * B / C (by considering only two reviews for simplicity)

The Defect Removal Efficiency (DRE) of an inspection process is also termed as Inspection Yield, which is Inspection Yield = Total Defects Found / Estimated Total Defects * 100 %Defect Removal Efficiency is a measure for the defect removal ability in the development process. This measurement can be either for the entire life cycle or for each phase of the development life cycle. Use of DRE at front end (before the code integration) is early defect removal and when used at specific phase, it is phase effectiveness. DRE = (Defects removed during a development phase / defects latent in the

product)* 100%Latent defects is the sum of defects removed during the phase and the defects found late

Inspection Time is the total inspection time measured in hours which is given by

Inspection Time = Sum of each reviewer’s review time + total person time spent in each meeting

Inspection Rate can be computed with the inspection time and the size of the artefact, which is measurable in terms of number of pages or LOC or other such measures as

Inspection Rate = Size / Total Inspection Time The defect detection Rate is estimated based on efficiency in detecting the defects which is computed as

Defect Finding Efficiency = Total Defects Found / Total Inspection Time

Above measures, thus quantify the outcome of inspection activity.

Review Efficiency = Total number of defects found by reviews /Total number of defects in product