RELIABILITY OF ELEMENTS OF THE COMPUTING SYSTEM AND ITS FAULT TOLERANCE

The system is given by a set of essential functions, and by a graph setting the environment for realization of these functions, and by the adequacy predicate establishing conditions of correspondence of the system graph to the set of the essential functions. This formal model allows to investigate tolerance of the system to the failures to be specified by the flow which is caused by a arbitrary factors, including and nonrandom. The flow of failures is assigned by a configuration space of the failed elements. Here a maximum value of the failure multiplicity is determined by the sum of a ceil value of the expectation of the number of a failed elementary machines (EM) and by the prescribed tolerance margin. The expectation is calculated subject to the workload of the system and to the distribution efficiency of this workload. The tolerance margin satisfies to acceptance criteria and allows for deviations of the real conditions of the system elements’ functioning from the normative ones.