Practical combinatorial (t-way) methods for detecting complex faults in regression testing

Regression testing can be among the most challenging of software assurance tasks because program changes often introduce faults, including unexpected interactions among different parts of the code. Unanticipated interactions may also occur when software is modified for a new platform. Techniques such as pairwise testing are not sufficient for detecting these faults, because empirical evidence shows that some errors are triggered only by the interaction of three, four, or more parameters. However, new algorithms and tools make it possible to generate tests that cover complex combinations of values (2-way to 6-way), or to analyze existing test suites and automatically generate tests that provide combinatorial coverage. The key advantage of this approach is that it produces better testing using a fraction of the tests required by other methods.