Test Strategies on the Basis of Extended Finite State Machines

While testing based on finite state machines has been extensively investigated in the literature, issues concerning testing based on extended finite state machines (EFSMs) have not been adequately addressed. Such a testing is complicated due to the fact that a transition in an EFSM transforms a large (sometime infinite) set of data in contrast to just one value in a finite state machine. Moreover, it is generally not possible to recognise, which transition has occurred in an EFSM. These problems manifest themselves in the relationship between function and trace test. In this paper we discuss these problems and present as solution two strategies separate function and trace test, and combined function and trace test for testing based on an EFSM.