Assuring the model evolution of protocol software specifications by regression testing process improvement

Model-based testing helps test engineers automate their testing tasks so that they are more cost-effective. When the model is changed because of the evolution of the specification, it is important to maintain the test suites up to date for regression testing. A complete regeneration of the whole test suite from the new model, although inefficient, is still frequently used in the industry, including Microsoft. To handle specification evolution effectively, we propose a test case reusability analysis technique to identify reusable test cases of the original test suite based on graph analysis. We also develop a test suite augmentation technique to generate new test cases to cover the change-related parts of the new model. The experiment on four large protocol document testing projects shows that our technique can successfully identify a high percentage of reusable test cases and generate low-redundancy new test cases. When compared with a complete regeneration of the whole test suite, our technique significantly reduces regression testing time while maintaining the stability of requirement coverage over the evolution of requirements specifications.