Prioritization of Metamorphic Relations Based on Test Case Execution Properties

A test oracle is essential for software testing. In certain complex systems, it is hard to distinguish between correct and incorrect behavior. Metamorphic testing is one of the solution to solve the test oracle problem. In metamorphic testing, metamorphic relations (MRs) are derived based on the properties exhibited by the program under test (PUT). These MRs play a major role in the generation of test data for conducting MT. The effectiveness of MRs can be determined based on the ability to detect considerable faults for the given PUT. Many metamorphic relations with different fault finding capability can be used to test the PUT and it is important to identify and prioritize the MRs based on its fault finding effectiveness. In order to answer this challenge, we propose to prioritize the MRs based on the diversity in the execution path of the source and follow-up test cases of the MRs. We propose four metrics to capture different levels of diversity in the execution behavior of the test cases for each of the derived MRs. The total weight calculated for each of the MRs using the metrics is used to prioritize the MRs.