In connection with the demonopolization and liberalization of the railway transportation market, as a result of the restructuring of JSC «Ukrainian Railways», which had a centralized approach to ensuring traffic safety, the support of this approach by independent operators is highly doubtful. Therefore, the issue of the development and application of mechanisms for external control of traffic safety in railway transport is of particular relevance. As one of the instruments of external control, including the interests of the state, JSC «Ukrainian Railways», private participants in the railway transportation market and potential investors, a technical audit can be used, which has already been widely used in other sectors of the economy. The features and effectiveness of technical audit in other sectors of the economy indicate the feasibility of its application in railway transport, however, the lack of legislative regulation of activities during a technical audit, a specific procedure and methods, require solving a certain range of tasks. Therefore, the topic of the dissertation is relevant.
The scientific novelty of the results obtained is as follows:
- for the first time, a mathematical model for risk assessment by priori, posteriori values and an integral assessment was developed, which is intended for external control of traffic safety on railway transport during the technical audit, on the basis of which a comprehensive characteristic of traffic safety, identification of possible threats and risk prediction can be given;
- for the first time, a mathematical model has been obtained for determining and predicting a potential (critical) hazard field during external control of traffic safety on railway transport, which allows determining measures or urgent actions to eliminate possible dangerous situations in transport processes;
- the operational model of risk management has been improved, which includes indicators of investment and operating costs, which, in contrast to the existing one, takes into account labor productivity, makes it possible to more accurately predict the number of violations of traffic safety in railway transport and implement risk management under external control;
- the system of risks was further developed, which, unlike the existing one, includes information on technical failures and violations of the transport process technology with the definition of general, integral, local, special and point risks, which allows, with external control, to more accurately characterize the current and predicted state of traffic safety on railway transport.
The practical significance of the results obtained. The scientific results obtained in the dissertation work, as well as the developed methodology and models can be used as methods of external control during the technical audit, as well as to solve the problem of assessing, predicting and improving traffic safety in railway transport.
The algorithm for performing calculations and plotting graphical dependencies in the process of conducting the technical audit for external control is implemented as a software application using the Microsoft Excel environment, which simplifies the auditor's work process and reduces the complexity of work.
The results obtained are used in the subdivisions of JSC «Ukrainian Railways».
As a result of the performed theoretical and experimental studies, given in the dissertation work, the scientific problem of the formation of methods for external control of traffic safety in railway transport was solved. Based on the proposed approaches and developed mathematical models, it is possible to identify and predict risks for further control, provision and improvement of traffic safety on railways, as well as to introduce an effective tool for external control of traffic safety by independent subjects of the railway transportation market.
Adequacy assessment was performed for the developed and improved models. So, for the mathematical model for assessing the risks of transport processes on the railways, the adequacy was determined by the Fisher criterion – the error was less than 11.5%; for the operational model of risk management, the coefficient of determination of which is equal to 0.9945 – the average relative error was 12.3%; for the integral assessment model, the adequacy was determined by the Pearson criterion – the error does not exceed 8.7%.
