Is Excel or any other spreadsheet effective for test case management? Is it convenient to use a spreadsheet at large projects with thousands of test cases? Is there any alternative? Definitely, yes. There is a variety of test case management systems.
Even 100% code coverage does not guarantee that your software is perfect. But code coverage metrics can help to optimize QA process, thus, save project budget. It is measured according to several levels like fucntion, statement, decision, condition (MC/DC & MCC), et.