Test Driven Design (TDD) and Design Driven Testing (DDT) are used for test case generation. TDD generates so many duplicated test cases at the end of the project. DDT is novel approach to generate test cases based on design model of application. Comparative study indicates batter result using DDT. White-box traditional regression testing depends on analysis of impact of changes in source code. This practice minimizes the amount of testing required to validate code changes but they do not influence on requirement specification. Black-box testing supports ability to test from higher level design and requirement. Test optimal is a tool to generate test cases based on model driven environment using UML activity diagrams.