| Much of the total life cycle of software is spent in the maintenance phase, during which a software system may undergo modifications in order to rectify discovered errors or to satisfy new or changing specifications. After these modifications have been implemented, the software is re-tested through the re-execution of predefined software test cases that were generated during earlier phases and the execution of new tests that correspond to the new specifications or new software structure. This regression testing seeks to achieve a degree of confidence that the software continues to perform in accordance with the desired behavior and that the modifications have not introduced errors into previously working portions of the software (regressions).;A prototype for an automated tool to reduce the effort required for software regression test planning is presented. It is a knowledge based tool which selects test cases for a regression test based on structural coverage criteria and identifies structural elements that remain untested. Index Terms: Software maintenance, regression testing, knowledge-based systems, structural testing, control flow, data flow, test coverage measures, test case selection, test plan update, test suite size, object-oriented testing.;The approach to regression testing should not simply involve the re-execution of all previous test cases, since not all of the test cases will have been affected and new test cases may also be required. Also, such an approach is not desirable as there is usually a very limited amount of time available to perform the regression test and analyze the results. What is preferred is that the portion of code that is affected by the modifications is sufficiently tested. To achieve this, test cases must be selected from existing ones in accordance with some test coverage adequacy criterion and new test cases developed where required. |
