Safety-critical applications have to fulfill stringent requirements, both functional and non-functional. These requirements have to be coherent with each other and must be preserved throughout the software development process. In this context, a design-driven development approach can play a critical role. However existing design-driven development approaches are often general purpose, providing little, if any, conceptual framework to guide the development. The resulting design scope thus becomes largely unpredictable, leading to inconsistencies. In this paper, we propose a design-driven method- ology that relies on a specific development paradigm. This development paradigm provides a conceptual framework that guides the stakeholders at each de- velopment stage. Based on this paradigm, a tool suite provides development support dedicated to each development stage. We demonstrate the benefits of this methodology with a realistic case study in the avionics domain.