Application of Kusumoto cost-metric to evaluate the cost effectiveness of software inspections

Inspections and testing are two widely recommended techniques for improving software quality. While testing cannot be conducted until software is implemented, inspections can help find and fix the faults right after their injection in the requirements and design documents. It is estimated that majority of testing cost is spent on fault rework and can be saved by inspections of early software products. However there is a lack of evidence regarding the testing costs saved by performing inspections. This research analyzes the costs and benefits of inspections and testing to decide on whether to schedule an inspection. We also analyzed the effect of the team size on the decision of how to organize the inspections. Another aspect of our research evaluates the use of Capture Recapture (CR) estimation method when the actual fault count of software product is unknown. Using data from 73 inspectors, we applied the Kusumoto metric to evaluate the cost-effectiveness of the inspections with varying team size. Our results provide a detailed analysis of the number of inspectors required for varying levels of cost-effectiveness during inspections; and the number of inspectors required by the CR estimators to provide estimates within 5% to 20% of the actual.