The main link in the logistics supply chain is the cargo customs complex. It provides customs and logistics services to cargo owners during the export and import of goods, complex services, placement of goods in a customs warehouse and a temporary storage warehouse. To substantiate the choice of the optimal logistics supply chain and optimize the work of the cargo customs complex, it is proposed to use simulation modeling. The model of operation of the logistics chain and the cargo customs complex is presented in a general form. The proposed model is implemented in the GPSS World simulation automation package. Testing the simulation model involved checking its adequacy. Checking the adequacy of the simulation model, which showed the maximum value of the t-statistic of 1.424 with a critical value of 1.85, proved its compliance with the work of a real object. After completing the adequacy check, the simulation error was estimated, which was 3 % with an allowable 5 %, due to the presence of pseudo-random number generators in the simulation model. Thus, the simulation error is insignificant for this study. For the cargo customs complex, an example of the simulation results is given. Based on the results of simulation modeling, it is possible to determine: the optimal type of the logistics supply chain and the optimal structure of the cargo customs complex. A wide range of tasks that the proposed simulation model can solve is presented. Thus, the developed simulation model will make it possible to analyze and improve the modes of operation of the cargo customs complex. In addition, it will allow to get an informed decision regarding the use of a certain type of logistics supply chain

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Operation efficiency assessment of cargo customs complexes located throughout Ukraine and having different technical, technological and organizational support levels can be made based on various technical and economic performance indicatorsThe paper develops the methodology for a comprehensive efficiency assessment of customs infrastructure facilities as an integral system of local measures and system performance indicators as a whole. Forming the integral criterion and the generalized integral criterion, we take into account the parameters of the benchmark cargo customs complex.The developed methodology for multi-criteria efficiency assessment of customs infrastructure facilities makes it possible to identify the groups of technical and economic performance indicators, to rank the technical and economic performance indicators according to the significance of their influence on the final generalized efficiency indicator; to form a vector with the parameters of the benchmark cargo customs complex; to determine the generalized efficiency assessment indicator of a cargo customs complex according to each group of factors; to determine the integral and generalized integral indicator of the operation of a cargo customs complex

The problems of railroad design technical reconstruction aimed at ensuring train protection in introduction of high-speed traffic on the rail lines have been addressed. The description of railroad technical system with certain specific features has been proposed. The pair of mutually dual problems regarding the optimal reconstruction of railway curves for raising train speeds at minimal capital investments has been addressed. The problem of determining the optimal speeds of trains of each category under optimum outer rail cant, increase of the unbalanced acceleration value, compliance with the condition of uniform load on rail tracks, comfortable carriage of passengers, in which reduced costs on increased speeds in curved tracks will be minimal has been formulated. To achieve the goals of the study, mathematical optimization techniques and algorithms of analysis of the rail lines of different nature are used. This, by finding and value engineering optimization, allows to minimize high-value and lengthy procedures of physical simulation. As a problem-solving technique, Lagrange multiplier method and its applicability have been proposed. Numeral solution to the problem of selection of certain stretches for increasing rolling stock speeds on operating lines without reconstruction or with minimum expenses on reconstruction of contour of track has been reviewed.

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