Equivalence Class Testing (U)

DO-178BC guidelines state that an expected activity associated with normal range test cases is that real and integer input variables be exercised using valid equivalence classes and boundary values, and that robustness test case activities include real and integer variables being exercised using equivalence class selection of invalid values. In this report, the meaning of this guideline is explored by a careful development of the concepts of equivalence class along with related concepts such as equivalence relation and the partition of a set. An example of the application of this guideline to white box testing is presented.