OASIS project
Stéphane Louise, Vincent David, Jean Delcoigne, Christophe Aussaguès · 2002
Safety critical systems is a growing industrial concern. It is a particular and long time interest for embedded or I&C systems, in nuclear power plant or aircraft applications. Since automotive industry is to use more and more microcontrollers or microprocessors with software in the near future[Bre01], concerns about safety of these systems is becoming mainstream. At the system level, because of intrinsic complexity, it is difficult to guarantee a high dependability. Typical applications should be able to manage numerous control tasks with several different time scales. They does not only demand correctness of algorithms, but also a correct management of tight time constraints, usually dictated by the environment. For system and application design, there is a conflicting interest between algorithm design and time scheduling design. Algorithm design favors a task per targeted control and so a multitasking approach. Time scheduling, on the other hand, has to take care of both strict and precise local chain of events, that needs a careful design in a multitasking environment, and mostly independent events at the system scale, more multitasking prone. One of the highest difficulties arises from the possible existence of very different time scales.