This paper presents the formalization of an innovative design process for automotive safety-critical systems. The objects and data used or produced throughout the different steps of the system design process (e.g. requirements, safety goals, functions, components, validation and verification activities…) are formalized in an integrated data model (or meta model). Besides the novel aspects of the design process, which will only be briefly mentioned in this paper, the originality of the approach lies on the combination of two normally independent models: a Systems Engineering data model and an Automotive Safety data model. The latter stems from the future ISO26262 standard relative to the safety of automotive embedded systems. The results presented in this paper are part of the Systems Engineering deployment initiative at Renault and represent the very first efforts aiming at the compliance with the future ISO26262 standard.