A. V. Morozov

In this article we consider the approach to an estimation of reserved systems reliability with the limited number of backups. The systems functioning in an independent mode, for example, military-oriented complexes, planes, the ships concern the given class. Nowadays thanks to modern achievements in electric chains components microminiaturisation the wide circulation was received by structural redundancy. The most widespread structural component is the duplicated group of elements. If one of the elements rejects the reserve element links up, and restoration of the fractured element consists in its replacement on efficient, taken of spare elements and accessories (ZIP). Restriction on restoration means, that the number of spare elements limited and does not replenish during the long period of independent work of system. Scientific novelty, the theoretical and practical importance of work consists in the developed technique allowing, unlike existing, not only to calculate probability of non-failure operation of the duplicated pair with a hot reserve and final number of spare elements, but also to produce offers by quantity of the spare elements providing the level of this proba-bility. Application of the described technique in practice allows counting probability of non-failure operation of the duplicated pair with a hot reserve and, accordingly, necessary quantity of spare elements in a case when average time of non-failure operation essentially surpasses average time of restoration. Scientific results of work can be used at designing and systems of different function creation which have restrictions on number restoration of given up elements.