Counter play-out: Executing unrealizable scenario-based specifications

Shahar Maoz, Yaniv Sa'Ar

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


The scenario-based approach to the specification and simulation of reactive systems has attracted much research efforts in recent years. While the problem of synthesizing a controller or a transition system from a scenario-based specification has been studied extensively, no work has yet effectively addressed the case where the specification is unrealizable and a controller cannot be synthesized. This has limited the effectiveness of using scenario-based specifications in requirements analysis and simulation. In this paper we present counter play-out, an interactive debugging method for unrealizable scenario-based specifications. When we identify an unrealizable specification, we generate a controller that plays the role of the environment and lets the engineer play the role of the system. During execution, the former chooses environment's moves such that the latter is forced to eventually fail in satisfying the system's requirements. This results in an interactive, guided execution, leading to the root causes of unrealizability. The generated controller constitutes a proof that the specification is conflicting and cannot be realized. Counter play-out is based on a counter strategy, which we compute by solving a Rabin game using a symbolic, BDD-based algorithm. The work is implemented and integrated with PlayGo, an IDE for scenario-based programming developed at the Weizmann Institute of Science. Case studies show the contribution of our work to the state-of-the-art in the scenario-based approach to specification and simulation.

Original languageEnglish
Title of host publication2013 35th International Conference on Software Engineering, ICSE 2013 - Proceedings
Number of pages10
StatePublished - 2013
Event2013 35th International Conference on Software Engineering, ICSE 2013 - San Francisco, CA, United States
Duration: 18 May 201326 May 2013

Publication series

NameProceedings - International Conference on Software Engineering
ISSN (Print)0270-5257


Conference2013 35th International Conference on Software Engineering, ICSE 2013
Country/TerritoryUnited States
CitySan Francisco, CA


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