First, we present the way the impact of ozone (O3) was already introduced into new or existing models (Kobayashi, 1997; AFRCWHEAT2-O3 with Ewert and Porter, 2000; Van Oijen et al., 2004 and CERES-O3 model with Lebard, 2005). Second, we discuss the way those approaches feed the conceptual framework of the new ozone module for the STICS model.