On the testing of particular input conditions

Generating test cases from a specification can be done at an early stage. However, so many important aspects relevant to testing can be identified from the specification that exhaustively testing their combinations can be very costly. A common approach to reduce testing costs is to identify some particular input conditions and test each of them only once. We argue that such an approach should be used judiciously, or else inadequate tests may result. This paper explores several alternatives to assess the validity of the tester's hypothesis that a particular condition can be tested adequately with only one test case. These alternatives help to test the particular conditions more reliably and, hence, reduce the risk of not revealing the existence of faults.