Scientific paper ID 1789 : 2019/3

In the current conditions in our country, although not at the desired pace, the production of components for incorporation in the products of world automobile production is increasing. In addition to new technological equipment in Bulgaria in this production is also used equipment, whereupon reducing the level of reliability is an increasing problem. That is why it is important to develop a toolbox for exploring the operational reliability of such complex technical sites. The present study examines the modeling of the reliable behavior of a complex technical object. The report explores the possibility of building a reliable model of a complex technical site - the main drive system of a CNC lathe with numerical control, by building a graph. Synthesis of the graph is carried out in several stages. At first, the objects that affect the operational reliability of the object under consideration are identified. The factors and processes influencing this reliability are then identified. These factors and processes are structured in groups. Based on pre-accumulated information on operating failures is a synthesized initial model in the form of a graph. Then based on the specific statistical data for the emergence of failures, this graph is approbated. Weighting coefficients are also determined of each of the factors and processes, which limit the operational reliability of the research object.