The main challenge of the PROARTIS project is to foster a paradigm shift from deterministic to randomised timing behaviour in CRTE (critical real-time embedded) systems. In the past, strong arguments that could be used in certification have been based on understanding the behaviour of the whole system at the level of processor cycle. This approach is becoming increasingly untenable in practicality, error proneness and cost against new-generation hardware technologies, including of course the pervasive multi core systems. The PROARTIS project moves away from timing-deterministic systems towards timing-randomised systems that exhibit truly independent timing behaviour and therefore enable the application of the law of large numbers to (probabilistically) predict the behaviour of extreme (i.e., long) execution times. The benefits of this novel approach are potentially very large. Strong emphasis is put in the project on the issues that may arise with regard to system validation and on the quantification of the benefits that the approach developed may bring.