Software testing plays an important role in software development because it can minimize the development cost. Any software two phases are considered, one is designing phase and other is testing phase. In designing phase system is designed which consists of all aspects of the system like its functions, operations and features. In testing phase test cases are generated to test the system in order to develop efficient software. UML is widely used in the software development, there consists of the designing and coding of the software. Designing phase is done with the help of the UML models, which consists of the sequence diagrams, activity diagrams, use case diagrams, state chart diagrams, etc.