Novel Strategy Generating Variable-length State Machine Test Paths

Finite State Machine is a popular modeling notation for various systems, especially software and electronic. Test paths can be automatically generated from the system model to test such systems using a suitable algorithm. This paper presents a strategy that generates test paths and allows to start and end test paths only in defined states of the finite state machine. The strategy also simultaneously supports generating test paths only of length in a given range. For this purpose, alternative system models, test coverage criteria, and a set of algorithms are developed. The strategy is compared with the best alternative based on the reduction of the test set generated by the established N-switch coverage approach on a mix of 171 industrial and artificially generated problem instances. The proposed strategy outperforms the compared variant in a smaller number of test path steps. The extent varies with the used test coverage criterion and preferred test path length range from none to two and half fold difference. Moreover, the proposed technique detected up to 30% more simple artificial defects inserted into experimental SUT models per one test step than the compared alternative technique. The proposed strategy is well applicable in situations where a possible test path starts and ends in a state machine needs to be reflected and, concurrently, the length of the test paths has to be in a defined range.