Babeshko I. Methods of information and control systems safety assessment and ensuring procedures complexation

Object of research – critical information and control systems and their reliability and safety assessment processes; the aim of research – to increase the functional safety of the I&CS by complexation of its assessment and ensuring procedures; research methods – methods of graph theory, methods of reliability and reconfiguration theory, methods of probability theory and Markov random processes with discrete states and continuous time; results – methods of functional safety assessment and ensuring information technology that allow to enhance functional safety of I&CS by reducing the risk of hazardous ICS failures through implementing the redistribution of channel redundancy etween subsystems of normal operation and safety / emergency protection management, as well as by reducing the risk of inaccuracy in the functional safety assessment when using several assessment procedures; novelty – for the first time, a method of procedural graph analysis of reliability and functional safety was proposed, which, unlike known ones, is based on a formal description and complexation of assessment procedures in the form of a meta-oriented graph, and generation and ranking their combinations based on the preference relationship, which allows selecting set of procedures for information and control systems reliability and safety ensuring at the design stage; improved the method of increasing the functional safety by taking into account the unreliability of the interlayer communications and the redistribution of resources to maintain the operability or provide emergency protection, basing on number and type of failures, which reduces the probability of the transition of systems to a hazardous state; the Markov models of information and control systems availability assessment have been further developed on the basis of accounting for various options of redundancy, recovery, and unequal reliability of components, which makes it possible to improve the accuracy of the assessment and to select a rational version of the structure and maintenance parameters, taking into account requirements to system reliability; the degree of implementation – the results were implemented at the Khartep Ltd, PE Promavtomatika-Kharkiv, National Aerospace University “Kharkiv Aviation Institute”, Ipra-Soft Ltd; industry – critical systems