Schedulability Analysis of Pre-runtime and Runtime Scheduling Algorithm of an Industrial Real Time System
The configuration of a complex, generic, real-time application into a specifically customized signalling embedded application has an important impact on time to market, deployment costs and safety guarantees for a railway signalling manufacturer. In this paper we focus on the aspect of real-time schedulability analysis, that takes an important portion of the time dedicated to configuration in this kind of systems. We propose an approach based on rigorous modelling of the scheduling algorithms, aimed at substituting possibly unreliable and costly empirical tuning. In order to comply with the needs of our industrial partners, we have resorted to the use of variants of Petri Nets with associated available tools: Timed Petri Nets (TPN) and Coloured Petri Nets (CPN), supported by open source tools, respectively TINA and CPN Tools 4.0 have been exploited for the modelling of the pre-runtime and the runtime scheduling algorithms implemented in the industrial platform. The comparison of models produced with the two tools has concluded that the Coloured Petri Nets are more suited to the adopted schedulability analysis approach, for both scheduling algorithms.
KeywordsPetri Nets Timed Petri Nets Coloured Petri Nets Real Time Systems Scheduling algorithm Modelling Formal verification Railway signalling
We wish to thank Marco Bartolozzi, Daniele Marchetti and Luca Santi for their contribution to the conducted modelling experiments.
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