Good practice for maintaining the Test Automation System (TAS) involves ensuring that the system is under configuration management, which includes the test suite, the testware artifacts, and the test environment. It also involves separating the test scripts from the environment and associated harnesses and artifacts to promote modularity and maintainability. Additionally, the TAS should be designed with replaceable components to allow for easy updates and changes without disrupting the overall system. However, stating that the TAS must run in the development environment because development and programming knowledge are required for its maintainability is not a good practice. The TAS should be able to run in multiple environments, and maintainability should not be dependent solely on the development environment or require development knowledge, as it should be maintainable by the testing team as well12345.

References = The ISTQB Test Automation Engineer (CT-TAE) certification materials and the associated syllabus provide guidelines on the best practices for maintaining the TAS, emphasizing the importance of configuration management, separation of concerns, and modularity12345.