Consider a TAS associated to dynamically changing software frequent releases.

The most crucial metric to collect in order to determine the maintenance effort for automated tests in a regression test suite, especially for a system under test (SUT) that undergoes frequent releases, is the number of automated tests requiring maintenance. This metric directly reflects the impact of changes in the SUT on the test suite. High maintenance needs can indicate that the automated tests are tightly coupled to the SUT, which may require a redesign of the test automation strategy to improve maintainability and reduce future effort.

References = The ISTQB Test Automation Engineer syllabus emphasizes the importance of metrics in monitoring the effectiveness of test automation. It specifically mentions the need to manage and optimize testing assets to facilitate maintainability, which aligns with the concept of measuring the number of tests requiring maintenance12.