Which of the following is NOT a purpose of metrics in software testing?

Metrics in software testing serve various purposes that aid in improving quality, assessing progress, and informing decision-making throughout the testing process. The primary functions of these metrics include measuring the extent of work completed, monitoring the effectiveness and efficiency of the testing effort, and gauging progress against defined milestones.

Identifying the percentage of work done in test environment preparation and test case preparation demonstrates how metrics can help track resource allocation and readiness, contributing to better planning and execution of the testing strategy. Measuring whether dates of test milestones were met is crucial for project management and ensuring timely delivery of the software product.

In contrast, the RAD (Rapid Application Development) model is a software development methodology, rather than a specific purpose of metrics in testing. While metrics can be utilized within various development methodologies to assess testing effectiveness, the RAD model itself is not a direct goal or function of test metrics. Therefore, this choice correctly identifies an aspect that does not align with the fundamental purposes of metrics in software testing.