The model-driven software development for hard real-time systems promotes the usage of the platform independent model as major design artifact. It is used to develop the software logic at a high level of abstraction and enables analysis like for example model checking of critical model properties. Ideally, starting with the platform independent model, the platform specific model serves only as an intermediate artifact which is derived automatically, and will finally result in a set of threads whose implementations guarantee the behavior, specified in the platform independent model. However, the current MDA approaches and tools for hard real-time software do not provide this ideal: While some of the MDA approaches could in principle support this vision, most approaches simply do not support an appropriate specification of time constraints in the platform independent model which have to be respected in the platform specific model or in the code. This is also true for UML models and ...