Developing generic models to simulate complex behaviors is one of the great challenges of numerical simulation. We present here a generic approach based on particle systems that has proved to be efficient in various kinds of complex situations, such as crown simulation or airbag deployment. In crown simulation each particle represents one person of the crown whose behavior is assigned according to the class it belongs to. In airbag deployment, both the gas mixture and the bag are modeled by particles. In this case, particles don't represent the molecules but abstract blocks chosen to reflect the macroscopic behavior of the system. By describing these two concrete applications, we intend to illustrate how our generic model can be successfully applied to a larger class of problems.