Formulation of the problem. The development of an approach to assessing the signaling reliability of combined intruder detection system is based on the binary logic of combining the simplest independent detector systems. Purpose. Assessment of the potentially achievable signaling reliability of the binary CSR and the development of proposals for the rational choice of the logic of its work. Results. The expressions for evaluating the mean time to false alarms of combined detection system is based on binary majority logic were refined, conditions for improving the work of CSR were identified. Practical significance. Methods for the protection of objects were developed for the rational construction of binary combined detection systems, which can be used in the construction of physical protection system of objects.