Coverage Analysis Methods for Formal Software Testing

Software creation requires not only testing during the development cycle by the development staff, but also independent validation following the completion of the implementation. However in the latter case, the amount of testing that can be carried out is often limited by time and resources. At the very most, independent testing can be expected to provide 100% coverage of the requirements (or specifications) associated with the software element. This report describes a methodology by which the amount of testing required to provide 100% coverage of the requirements is assured while at the same time minimizing the total number of tests included in a test suite. A collateral procedure provides recommendations on which tests which might be eliminated if less than 10O% coverage of the requirements is permitted. This latter process will be useful in determining the risk of not running the minimum set of tests for 100% coverage. A second process selects from the test matrix the set of tests to be applied to the system following maintenance modification of any module-- that is, to provide a submatrix for regression testing.