Test Case Prioritization for Regression Testing based on Severity of Fault

Regression testing is one of the most critical activities of software development and maintenance. Whenever software is modified, a set of test cases are run and the comparison of new outputs is done with the older one to avoid unwanted changes. If the new output and old output match it implies that the modifications made in one part of the software don’t affect the remaining software. It is impractical to re-execute every test case for a program if changes occur. The problem of regression test case selection can be solved by prioritizing the test cases. Regression test prioritization techniques reorder the execution of a test suit in an attempt to ensure that faults are revealed at the earlier stage of the testing process. Test case prioritization techniques schedule test cases for execution so that those with higher priority, according to some criterion are executed earlier than those with lower priority to meet some performance goal. In this paper an algorithm is proposed to prioritize test cases based on rate of fault detection and fault impact. The proposed algorithm identifies the severe fault at earlier stage of the testing process and the effectiveness of prioritized test case and comparison of it with unprioritized ones with the help of APFD. KeywordsRegression Testing, Test Case, Average Percentage of Faults Detected (APFD).