The task of maintaining the operability of complex technical systems is one of the important tasks of ensuring the reliability in high-rise construction. It is solved at all stages of the life cycle of the device. Ensuring high availability of technical devices for use during the operational phase is the timely conduct of preventive measures and routine maintenance. To this end, the repair authorities have in their inventory material resources to replace the abandoned and end-of-life elements, as well as the production facilities necessary to perform the repair itself. One of the possible variants of this method of repair can be the creation and use of significant production capacities of repair enterprises that do not need material resources, and carry out repairs themselves. Another option may be a large range of spare parts, which will make an additional link repair company. The paper considers the issues of creating a rational organization of repair of complex technical systems. At the same time, one of the important practical tasks is the task of determining the rational relationship between the production capacities of repair enterprises and the amount of reserves needed to perform repairs. The development of the initial theoretical provisions on the rationale for the rational correlation of the volumes of spare parts and production capacities of repair enterprises to the effective use of reserves is devoted to this article.