Abstract: In a trajectory-based operations’ environment, at some time during the planning phase, shared business trajectories will become reference business trajectories, and not necessarily conflict free. This paper presents a way of obtaining a conflict-free solution for all planned trajectories during the strategic phase (before becoming reference business trajectories). The proposed methodology incorporates 1) a data-driven conflict-resolution model, and 2) a multiobjective global optimization that considers the interests of a variety of actors in the air traffic management community: particularly, air navigation service providers and airlines.