On Conformance Testing for Timed Systems

  • Julien Schmaltz
  • Jan Tretmans
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5215)


Conformance testing for labeled transition systems starts with defining when an implementation conforms to its specification. One of the formal theories for model-based testing uses the implementation relation ioco for this purpose. A peculiar aspect of ioco is to consider the absence of outputs as an observable action, named quiescence. Recently a number of real-time extensions of ioco have been proposed in the literature. Quiescence and the observation of arbitrary delays are issues when defining such extensions. We present two new timed implementation relations and show their relation with existing ones. Based on these new definitions and using several examples, we show the subtle differences, and the consequences that small modifications in the definitions can have on the resulting relations. Moreover, we present conditions under which some of these implementation relations coincide. The notion of M-quiescence, i.e., if outputs occur in a system they occur before a delay M, turns out to be important in these conditions.


Output Action Label Transition System Forced Input Observable Action Conformance Test 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Alur, R., Dill, D.L.: A theory of timed automata. Theoretical Computer Science 126(2), 183–235 (1994)zbMATHCrossRefMathSciNetGoogle Scholar
  2. 2.
    Bohnenkamp, H., Belinfante, A.: Timed Testing with TorX. In: Fitzgerald, J.S., Hayes, I.J., Tarlecki, A. (eds.) FM 2005. LNCS, vol. 3582, pp. 173–188. Springer, Heidelberg (2005)Google Scholar
  3. 3.
    Brandan-Briones, L.: Theories for Model-based Testing: Real-time and Coverage. PhD thesis, University of Twente, Enschede, The Netherlands (2007)Google Scholar
  4. 4.
    Brandán Briones, L., Brinksma, E.: A Test Generation Framework for quiescent Real-Time Systems. In: Grabowski, J., Nielsen, B. (eds.) FATES 2004. LNCS, vol. 3395, pp. 64–78. Springer, Heidelberg (2005)Google Scholar
  5. 5.
    Hessel, A., Larsen, K.G., Mikucionis, M., Nielsen, B., Pettersson, P., Skou, A.: Testing Real-Time Systems Using UPPAAL. In: Hierons, R.M., Bowen, J.P., Harman, M. (eds.) FORTEST. LNCS, vol. 4949, pp. 77–117. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  6. 6.
    Khoumsi, A., Jéron, T., Marchand, H.: Test cases generation for nondeterministic real-time systems. In: Petrenko, A., Ulrich, A. (eds.) FATES 2003. LNCS, vol. 2931, pp. 131–146. Springer, Heidelberg (2004)Google Scholar
  7. 7.
    Krichen, M., Tripakis, S.: Black-box conformance testing for real-time systems. In: Graf, S., Mounier, L. (eds.) SPIN 2004. LNCS, vol. 2989, pp. 109–126. Springer, Heidelberg (2004)Google Scholar
  8. 8.
    Krichen, M., Tripakis, S.: An expressive and implementable formal framework for testing real-time systems. In: Khendek, F., Dssouli, R. (eds.) TestCom 2005. LNCS, vol. 3502, pp. 209–225. Springer, Heidelberg (2005)Google Scholar
  9. 9.
    Krichen, M., Tripakis, S.: Interesting properties of the real-time conformance relation tioco. In: Barkaoui, K., Cavalcanti, A., Cerone, A. (eds.) ICTAC 2006. LNCS, vol. 4281, pp. 317–331. Springer, Heidelberg (2006)CrossRefGoogle Scholar
  10. 10.
    Larsen, K.G., Mikucionis, M., Nielsen, B., Skou, A.: Testing real-time embedded software using uppaal-tron: an industrial case study. In: EMSOFT 2005: Proceedings of the 5th ACM international conference on Embedded software, pp. 299–306. ACM, New York (2005)CrossRefGoogle Scholar
  11. 11.
    Larsen, K.G., Mikucionis, M., Nielsen, B.: Online Testing of Real-Time Systems using Uppaal. In: Grabowski, J., Nielsen, B. (eds.) FATES 2004. LNCS, vol. 3395, pp. 79–94. Springer, Heidelberg (2005)Google Scholar
  12. 12.
    Tretmans, J.: Test Generation with Inputs, Outputs and Repetitive Quiescence. Software - Concepts and Tools 17(3), 103–120 (1996)zbMATHGoogle Scholar
  13. 13.
    Tretmans, J.: Model Based Testing with Labelled Transition Systems. In: Hierons, R.M., Bowen, J.P., Harman, M. (eds.) FORTEST. LNCS, vol. 4949, pp. 1–38. Springer, Heidelberg (2008)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Julien Schmaltz
    • 1
    • 2
  • Jan Tretmans
    • 1
    • 2
  1. 1.Institute for Computing and Information SciencesRadboud University NijmegenNijmegenThe Netherlands
  2. 2.Embedded System Institute EindhovenThe Netherlands

Personalised recommendations