Research On Simulation And Optimization For Processes Of A Container Motor-Rail Multimodal Transportation System

At present, with the development and progress of economy and management technology, the container sea-rail combined transportation gradually develops into container motor-rail multimodal transportation from the coastal to inland. However, there is less study on the operation processes of container motor-rail multimodal transportation system at home and abroad, and the most focuses on the current situation and trends, management mode etc. The thesis applies modeling and simulation technologies to study the processes of container motor-rail multimodal transportation system in order to shorten the process time of the system and improve the system efficiency.Based on the process modeling and simulation technology of container motor-rail multimodal transportation at home and abroad, IDEF3is used in modeling and analyzing processes of container motor-rail multimodal transportation system. Meanwhile, the resource in the system has been studied. Then, the universal hierarchical process model of Petti Nets for a container motor-rail multimodal transportation system is established according to the transformational rules from IDEF3to Petri Nets; afterwards, the incidence matrix method is used in analyzing mathematical structure features of the Petri Nets process model, which is proved that the Petri Nets model is reachable, bounded and live.The ExSpect software is chosen to further analyze and optimize the processes of motor-rail multimodal transportation system, taken Xinjiang container motor-rail multimodal transportation system as a case study according to the established Petri Nets model. Through simulation, the system process time is analyzed. At the same time, the "door to door" and "cfs to cfs"(container freight station to container freight station) transportation modes have been analyzed using ExSpect. Based on the simulation results, the critical paths of the processes for a container motor-rail multimodal transportation system have been found. Finally, according to the critical paths, the thesis provides three alternative process optimization schemes from the view of the time in the critical paths and process structure. The simulation results show these schemes can reduce the system time and enhance system operating efficiency.