In the process of operation, the interval coefficient of readiness of technical systems in the agro-industrial complex should correspond to the strategy of trouble-free operation in the interval of time required to perform the required amount of work, or technological operation in the production of agricultural products. Improving and maintaining the reliability of technical systems in the agro-industrial complex is largely determined by the perfection of methods and reliability management system. Currently, a lot of models of reliability management have been developed, which allow to quantify the results of management and purposefully influence these results in the required direction. The issues of reliability management at the stages of design and serial production of technical systems are most fully developed in them and much less - at the stage of their operation. However, the management of the reliability of technical systems at the stage of their operation, which consists in maintaining the level of reliability of the devices provided by the manufacturer, implemented by means of justification, appointment and execution for the available or specified time of the complex of measures for their technical and technological maintenance, is no less important task. The structural scheme of management of reliability of technical systems in agro-industrial complex, including strategic management of reliability, carried out at the stages of design and production of technical systems and operational management of reliability, carried out at the stage of operation of technical systems in the real conditions of agro-industrial enterprises. Introduced the concept of «Functional operational diagnosis» - a complex of measures, directed on increase of reliability of technical systems and their elements due to technology and means of rapid diagnosis, redundant from the point of view of classical domestic strategies of maintenance and repair of machinery, but is necessary to ensure absolute reliability interval. The block diagram of functional operational diagnostics of technical systems in the agro-industrial complex and their elements is developed.