SUMMARY
Purpose. Inspection and observation of the technical level of rail locomotive repair productions are conducted by the management team of the Department and the Locomotive division, audit sectors, expert groups within the production certification procedure. The faults revealed are fixed as linguistic expert reports which cannot assess their significance and identify priorities in terms of elimination. The paper aimed the development of methods for the conformance rating for locomotive repair production to legal requirements with conformance level determination. Methodology. Formalization of linguistic reports on the locomotive repair facility conformance takes into account the influence of a whole number of factors, their significance being determined by the expert assessment, formalized models of events when designing and analyzing the fault tree. In order to calculate the conformance, index the triple additive convolution with the weight coefficient is proposed. Investigation into interrelation between the integral index and the locomotive maintenance costs was conducted by methods of the correlation and regression analysis. Findings. The analysis of results of inspection and observation of the technical level of locomotive repair productions demonstrated a similar structure of expert reports on faults, which made it possible to present them as a vector. While transforming a multi-criterion problem into a single-criterion one of the most objective method, the weighted sum method, was applied. The conformance indices were calculated according to the results of observations on several locomotive repair productions. The correlation and regression analysis proved the influence of the conformance index of locomotive repair productions on locomotive maintenance overconsumption. Originality. The conformance rating methods for a technical level of locomotive repair productions based on linguistic expert reports which consider type of the fault detected, type of the technological process, type of the locomotive unit and type of the technical level of production have been designed. Practical value. Implementation of the methods designed will help undertake assessment of the faults detected, eliminate them according to the priority and invest more effectively in locomotive repair productions. The regressive equations obtained allow standardizing the conformance index and forecasting possible locomotive maintenance overconsumption by the results of inspection at repair productions.