A well-established method for measuring the quantitative value and efficiency of testing is called cost of quality (or, sometimes, cost of poor quality).
It involves classifying project and operational costs into four categories related to product defect costs:
- Costs of prevention training developers to write more maintainable or secure code
- Costs of detection writing test cases, configuring test environments, and reviewing requirements
- Costs of internal failure fixing defects detected during testing or reviews, prior to delivery
- Costs of external failure support costs associated with defective software delivered to customers