In this paper we discuss the separation between attributes on functionality and on structure following an approach based on Model Driven Engineering (MDE). We adopt a methodological approach based on correctnessby-construction for modeling high-integrity real-time embedded systems. We illustrate how this separation is implemented by a prototype, recently realized by our research team. Software reuse is incremented by using the prototype. This has been confirmed by the evaluation of two teams from major European space industry. We conclude our work by discussing some open problems.