We know that different intelligent instruments play an important role in the evolution of various industrial systems dependability. This role is mainly due to the additional functionality of the compensation, validation, self-diagnosis and self-configuration functions, combined with appropriate means of communication. For this reason, this article presents an in-depth study of the contribution of intelligent instruments for improving mechatronic system dependability. In this paper, we note that the indicators taken into account as an evaluation criterion is the probability of dangerous failure (PFD) and the probability of safe failures (PFS). To carry out this study, three modeling approaches of functional and dysfunctional behavior of studied system in the classical case and intelligently face, namely: fault tree, reliability diagram and