Increase of reliability level of information systems

In the presented work the question of increase of reliability level of information systems is considered. The problem is solved by creation of mathematical model of information system, as the special case possessing increased requirements to level of reliability, the system of electronic document flow is taken. In this work the analysis of existing methods of an assessment of reliability level of information systems is carried out, the methods allowing to raise reliability level of information system at various operational phases of information system are also considered. Within the methods of an assessment of reliability level of information systems methods of forecasting of level of reliability of information system, and also probability of emergence of mistakes are considered at operation of information system. Within the carried-out work the authors have combined the algorithm of increase of reliability level of information system, in the conditions of need of continuous operation of information system on the basis of application of methods of mathematical modeling was created. The work of the combined method also includes the work of a dynamic method of an assessment of reliability level of information system which is the indicator of achievement of an optimum condition of reliability level of information system. The results of work can be applied to carry out pilot studies concerning ensuring information security, optimization of work of information systems.