Software pervades every aspect of life: business, financial services, medical services, communication systems, entertainment, and education are invariably dependent on software. With this increasing dependency on software, we expect software to be reliable, robust, safe, and secure. Testing remains the primary way to improve reliability of software. Testing is an essential part of software development providing an indicator of the quality of the software. We focus on the issue of class testing. The biggest advantage of Test at First framework provides us with factor like test case reusability. The test case process can be rated as high if it promises lesser testing efforts or have good testability. Test case design metrics are very useful in evaluating the quality of test case and the software development process. A thorough study of different metrics sets and by combining significant metrics proposes a modified set of Automated Test Case for Unit Testing (ATCUT) design metrics. This proposed set is completer and more direct in incorporating the concept of optimization of automated test case design for unit testing.