THE COMPARATIVE ANALYSIS OF CALCULATION METHODS OF INDICATOR OF FUNCTIONAL STABILITY OF INFORMATIONS SYSTEMS ON EXAMPLE ON FULL OVERHAUL AND LYTVAK-USHAKOFF METHOD

Abstract

Against the background of active development of information systems and increasing requirements for them, the variety of their design methods is increasing. Research in this sphere is quite broad, and therefore there are more and more diverse aspects that must be studied. However, despite the large number of topics and problems studied, they can be conventionally divided into two categories: technical and theoretical. The first category, as a rule, includes research related to the development of technical support for information systems. Despite this, no less important are problems of a more theoretical nature, which, in turn, study the problems of optimal placement and distribution of means, establishing their number, system reliability, etc.

One of the most relevant areas of research in this area is the assessment of various criteria and indicators of the functional stability of the system. Functional stability means the system's ability to at least partially perform basic functions against the background of negative external influences. Its main indicators include the so-called probability of connectivity, which is the probability of exchanging messages between network subscribers. Against this background, a number of both exact and approximate methods of calculating this probability have been developed. However, each of them has its advantages and disadvantages, and therefore the question arises when comparing them.

Of particular practical interest is the question of whether it is better to use a more complex but accurate method of calculating the probability of data transmission between subscribers or a simpler but approximate one? For this purpose, this paper conducts a comparative analysis of known methods, namely, the method of complete enumeration and the Litvak-Ushakov method. Their general essence is presented and their use is demonstrated on a concrete example. Their advantages and disadvantages in relation to each other are considered and a general conclusion is made regarding the specifics of their application.