Parametric model checking timed automata under non-Zenoness assumption

• Main Authors: ANDRE, Étienne, NGUYEN, Hoang Gia, PETRUCCI, Laure, SUN, Jun
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2017
• Subjects: Automata theory; Formal methods; Interactive computer systems; NASA; Real time systems; Software Engineering
• Online Access: https://ink.library.smu.edu.sg/sis_research/4714; https://ink.library.smu.edu.sg/context/sis_research/article/5717/viewcontent/Parametric_model_checking_non_Zenoness_av_2017.pdf
• Institution: Singapore Management University

Real-time systems often involve hard timing constraints and concurrency, and are notoriously hard to design or verify. Given a model of a real-time system and a property, parametric model-checking aims at synthesizing timing valuations such that the model satisfies the property. However, the counter-example returned by such a procedure may be Zeno (an infinite number of discrete actions occurring in a finite time), which is unrealistic. We show here that synthesizing parameter valuations such that at least one counterexample run is non-Zeno is undecidable for parametric timed automata (PTAs). Still, we propose a semi-algorithm based on a transformation of PTAs into Clock Upper Bound PTAs to derive all valuations whenever it terminates, and some of them otherwise.