Functional Dependence and Equivalence Class Factors in Combinatorial Test Designs

Functionally dependent (FD) mappings permeate software systems and impose constraints on designs for verification. This paper develops concepts for accommodating FD relations in combinatorial test designs and derives rules to determine combinatorial coverage for FD factors. FD equivalence class factors are introduced to assess coverage of expected results classes before test case generation. Examples are given for test designs with FD factors, for applications of the coverage rules, and for coverage improvement techniques. A nondeterminant strength classification is formulated.