Test suites derivation for nondeterministic finite state mashines with respect to the separability relation

In this paper we improve test suite derivation method for nondeterministic FSMs with respect to the nonseparability relation. The nonseparability relation can be checked when “all weather conditions” assumption does not hold. Our modification is based on the refinement of tree truncation conditions. It is shown that test suites constructed according to the method with our improvements are (in most cases) shorter and still complete.