Design for Time-Predictability

A large part of safety-critical embedded systems has to satisfy hard real-time constraints. These need sound methods and tools to derive reliable run-time guarantees. The guaranteed run times should not only be reliable, but also precise. The achievable precision highly depends on characteristics of the target architecture and the implementation methods and system layers of the software. Trends in hardware and software design run contrary to predictability. This article describes threats to time-predictability of systems and proposes design principles that support time predictability. The ultimate goal is to design performant systems with sharp upper and lower bounds on execution times