Abstract. In this paper, reverse partially-marked safe net condition/event systems (RsNCES) are introduced, rules of their functioning are defined and convenient interpretation methods are suggested. The RsNCES are based on the ordinary safe NCES in which so-called backward firing rules for transitions and steps are accepted. Using of partial markings allows reducing the number of reachable states in the net models. RsNCES interpretation methods are based on the representation of net models in the form of Boolean functions and their subsequent minimization. An algorithm for RsNCES reachability graphs building is proposed. RsNCES can be applied to analyze the ordinary safe NCES as well as to synthesize a safety control, for example, in industrial automation.