Determining the reliability of network information systems

Mathematical support of reliability analysis of network information systems is developed. As a model, the network information system uses a graph representation based on the formalization of the graph description by parent projections. In this paper, a new operation is introduced on the parent projection of the graph - the operation of removing the vertex from the graph and then contracting the edges incident to the remote vertex. An algorithm for cutting the graph of a network information system is proposed based on the well-known technique of using paths and sections. The state tree of the system, obtained as a result of the implementation of the algorithm for cutting the parent projection of the graph, illustrates the development of failures within the system before the onset of an inoperative state and is a structural function of the original graph. Based on the resulting combination of projections obtained as a result of the implementation of the cutting algorithm, a probabilistic reliability function is constructed.