SIMULATION AND OPTIMIZATION OF FREIGHT CUSTOMS COMPLEXES` BASED ON QUEUEING SYSTEMS
Transport systems and transportation technologies
The purpose of the article is to create a simulation model for the study and optimization of a freight customs complex's structure when performing export and import operations, comprehensive service provision, and the stowage of goods in a customs warehouse or a temporary storage warehouse. Methodology is the simulation modeling of queuing systems. The mathematical model of the freight customs complex (FCC) is presented as a queuing system. The simulation model of the freight customs complex
... been developed in the GPSS World simulation automation package. The simulation model was tested including two stages -verification and validity check. Studying the properties of the model, simulation accuracy was estimated; the length of the simulation transition period was determined; the stability of simulation model responses was evaluated; the sensitivity of model responses to changes in the number of vehicles requiring service was determined. Findings. Based on the developed simulation model, it was conducted the study on customs and logistics service operations provided for freight owners in the export and import of goods, comprehensive servicing, and freight storage in a customs warehouse and a temporary storage warehouse. The simulation model validation results at one of freight customs complexes in the Kyiv region are presented. Originality consists in the opportunity to research the processes at freight customs complexes using simulation modeling with the different degrees of detail and over time optimizing its structure. Practical value. The developed simulation model of the freight customs complex provides an opportunity to identify the average time spent by vehicles on the territory of the freight customs complex when performing export and import operations, comprehensive service provision, and the stowage of goods in a customs warehouse and a temporary storage warehouse; the probability of service refusal due to the lack of parking spaces for vehicles in the customs control zone; the optimal number of customs inspectors and vehicle parking spaces; the optimal sizes of warehouse space for placing freight in a customs warehouse or a temporary storage warehouse. This will make it possible not only to analyze the operation of the freight customs complex but also to optimize its structure, to determine measures that will increase the throughput capacity of the freight customs complex.