One of the hardest automatic driving tasks in the field of intelligent vehicles is collision avoidance. More drivers are often use to braking than to steering in emergency situations, even if the steering is the best maneuver. Manual steering is less effective at avoiding obstacles than automatic emergency steering. Braking, accelerating, steering, or a combination of braking, accelerating & steering can be used to prevent a collision. Because of the complexity involved, the automatic emergency steering system must be designed using a Model-Based Systems Engineering (MBSE) methodology. Only steering interventions are considered in this paper.