Bow tie diagram has become a popular method to implement safety barriers. It defines several preventive and protective barriers to reduce respectively the frequency and severity of a given risk. These barriers are often defined by experts that ignore the real aspect of the system. However, the definition of barriers based on experts experiences limits this method because it seems unrealistic to use static recommendations in real dynamic systems. This paper proposes a new multi-objectives approach to implement preventive and protective barriers. The proposed approach is mainly based on three phases namely; a parameters learning phase, a simulation phase and a selection phase. (C) 2014 Elsevier Ltd. All rights reserved.