Studying the separability relation between finite state machines
Article first published online: 21 AUG 2007
Copyright © 2007 John Wiley & Sons, Ltd.
Software Testing, Verification and Reliability
Volume 17, Issue 4, pages 227–241, December 2007
How to Cite
Spitsyna, N., El-Fakih, K. and Yevtushenko, N. (2007), Studying the separability relation between finite state machines. Softw. Test. Verif. Reliab., 17: 227–241. doi: 10.1002/stvr.374
- Issue published online: 13 NOV 2007
- Article first published online: 21 AUG 2007
- Manuscript Accepted: 6 JUL 2007
- Manuscript Revised: 14 JUN 2007
- Manuscript Received: 27 MAR 2006
- finite state machines;
- separability relation;
- conformance testing
Several authors have studied the relationships between non-deterministic finite state machines (FSMs). These relationships can be used, for example, for deriving conformance tests from specifications represented by FSMs. In this paper, the separability relation between FSMs is studied. In particular, an algorithm is presented that derives a shortest separating sequence of two non-deterministic FSMs. Given FSMs S with n states and T with m states, it is shown that the upper bound on the length of a shortest separating sequence is 2mn−1. Moreover, the upper bound is shown to be reachable. However, according to the conducted experiments, on average, the length of a shortest separating sequence of FSMs S and T states is less than mn and the existence of a separating sequence significantly depends on the number of non-deterministic transitions in these FSMs. The proposed algorithm can also be used for deriving a separating sequence of two different states of a single FSM or for deriving a separating sequence of three or more FSMs. Copyright © 2007 John Wiley & Sons, Ltd.