Software testing is usually measured by executing the 'n' number of test cases and those test cases has to be designed using the familiar test case design techniques. The aim of Test case design technique is to ensure the detection of typical bugs, systematic coverage and redundant testing. Executing and checking the test cases is not possible all the time in the manual testing. Therefore selecting a test case and ranking is important. The objective of the test case selection is to have a better test case from a pool of test cases and assigning the rank to each test case will leads the software asan error free and which gives a good efficiency. Ranking of test cases is especially useful if a system is a having large number of test cases. Hence selecting and ranking a test case plays an important role in the software testing. In this paper, importance of selection and ranking test cases are analysed and its methods are discussed. © 2006-2016 Asian Research Publishing Network (ARPN).