The quantitative methods of risk assessment of technological processes of manufacture and the analysis of level of deficiency of products in the conditions of nondeterministic stochastic parameters are considered. The properties defining reliability of process are its controllability, stability and reproducibility. The main methodical device by assessment and the analysis of these properties are provisions of standards on statistical methods of quality control. In the analysis and assessment of risk it is necessary to consider that borders of a tolerance zone of parameters of products and control limits of reliability of technological processes of its production are always considered as acceptable (admissible) risk levels. Overcoming these levels is considered a negative consequence in the form of increase in level of deficiency of products and decrease in accuracy of technological processes of its production. Technical solutions are always bound to risk as it is never impossible to be sure of the end estimated result in advance. To check whether this risk was justified, it is possible always only after realization of technical solution and approach of an undesirable event. Therefore technical activity in principle can't be completely free from any risk, and it is always necessary to go on necessary and justified risk consciously.

Keywords: technical system, technological process, risk, indeterminacy, management of reliability, negative event, damage, nondeterministic stochastic parameter

The article presents a description of the device for determining the physicomechanical characteristics of bulk materials - coefficients of external and internal friction. In DSTU, a device for determining the friction characteristics of bulk materials was designed and manufactured. A method for determining the coefficients of static and dynamic friction is presented. The proposed device allows to obtain more accurate information about the frictional characteristics of one or different bulk materials in static and dynamic conditions.

Keywords: Friction, dynamic coefficient of friction, static coefficient of friction, bulk material

The problem of control of strength characteristics of agricultural machine parts by dynamic non-destructive methods of impact indentation of conical shape is considered. The quality of the most important parts is considered in terms of the set of mechanical characteristics that determine the strength, hardness, wear resistance and deformability. These characteristics should be known and be able to quickly and accurately control all parts both during production and during operation. The mechanical properties of metals are stochastic. For this purpose, a device for impact indentation was developed and a method based on the probabilistic laws of dispersion of mechanical characteristics was developed.

Keywords: agricultural machines, reliability, quality control, mechanical characteristics, Weibull law, non-destructive testing, impact indentation