The difficulty of ensuring dependability, the growth of the scale of software and software testing, in many cases, sufficient software testing is not possible. In particular, although reliable systems such as high-availability servers are parallel and distributed systems, it is often difficult to test a parallel and distributed system in the real world after deployment. Highly dependable systems must have some mechanism for fault tolerance in software testing. In our proposed system we introduce the clustering approach for grouping the test cases. Before that we generate the test case for the model using functional requirements. These test cases are analyzed for measure their relevancy and relationship between the test cases using their constrains. After measuring this relevancy and relationship based cosine similarity we clustering the test cases. Each clusters are distributed to the distributed environment for parallel execution. Integrity mechanism will helps us to integrate the test results from the distributed environment. Through this we have to achieve the less computing time for testing and also reduce the failure ratio for testing software’s.