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International audienceThis paper presents the initial step of an aid design method earmarked for operational validation of hard real-time systems. We consider systems that are composed of sequential hard real-time tasks, which are embedded on centralized multiprocessor architectures. We introduce a model based upon untimed finite automata and meant to collect the operational behaviors of the system compatible with its time specifications, and we go on to provide a feasibility decision result for systems composed of tasks presenting CPU loads which are exact values: execution times are not WCET values. This is why we call this approach WCET-free analysis. The results we have achieved likewise involve hardware specifications such as multiprocessors and speeds of processors

Abstract. Off-line validation of hard real-time systems usually stands on state based models. Such approaches always deal with both space and time combinatorial explosions. This paper proposes a discrete geometrical approach to model applications and to compute operational feasability from topological properties. Thanks to this model, we can decide the feasability of real-time synchronous systems composed of periodic tasks, sharing resources, running on multiprocessor architectures. This method avoids state enumeration and therefore limits both space and time explosion: computing an automaton model takes at least 2 hours for a real application instead of at most 1 second using discrete geometry.