Ponochovnyi Y. Methodological bases and information technologies to ensuring the dependability of information and control systems with multi-goal maintenance

Continuous safeguard operation of ICS today is an undisputed priority for various industries, ensuring the livelihood of people and society. In recent years, the issues of complex providing of dependability indicators for normal functioning of ICS have become relevant. These issues have previously been singled out in various disciplines, including reliability theory, functional safety theory, and information and cybersecurity theory. Thus, there is a contradiction between the dependability requirements, accuracy of its assessment for maintenances or partially maintenances ICS in conditions of their evolution due to changes in the goals and parameters of the physical and information environment, manifestations of unspecified failures due to software and hardware defects and vulnerability attacks, one side and the imperfection of the existing scientific and methodological tools, absence models, methods and tools of information technology, which would allow you to design and select the appropriate ones maintenance strategies and their parameters by indicator’s reliability, availability, functional safety, security and dependability as a whole. The main results of the dissertation research are: methodological bases, concept and principles of dependability ensuring of maintained ICS; models of multi-goal maintenance strategies of ICS; method of assessment the parameters of the dependable ICS; a system model of multigoal maintenance procedures, which describes the set of states and relationships between the processes of testing, online verification and updating within the basic fragments and the relationship between them, forms a set of multi-fragment models of ICS with updated software; multi-fragment models for availability assessment of ICS in the event of unspecified failures, attacks on vulnerabilities and changes in environmental parameters by taking into account the procedures of patching, online verification and proof testing; multiphase model for dependability assessment of ICS, which takes into account different maintenance strategies with deterministic periods and random maintenance duration; simulation models for dependability assessment of ICS using the proposed procedures for statistical evaluation of the distribution of the resulting indicators; the method of selecting the parameters of maintenance procedures to dependability ensuring of ICS, which takes into account the different options for multigoal maintenance procedures with the elimination of defects and vulnerabilities.