A Regression Testing Technique based on the Z Formal Language

Regression testing is an important area of software testing, which is carried out after software maintenance. Many techniques have been developed for this purpose including model based, component based, and code based testing. In addition to above techniques, other approaches exist named as formal specification based testing techniques. Regression testing can be performed using formal specifications in such scenarios. The increased use of formal methods in the software industry has increased the importance of formal specification based testing techniques. Though formal methods are increasingly used in the software industry there is very little work done as for as the formal specification based regression testing is concerned. This paper presents a new approach to regression testing based on Z formal notation. The approach presented in this paper is for the purpose of classifying the test cases from original test suite into three classes obsolete, retestable, and reusable test cases. This technique not only classifies the original test cases but it also generates new test cases required for the purpose of regression testing. The approach is evaluated using a case study.