Research Of Multimodal Transportation Process Optimization Based On Petri Net

With the acceleration of the global economic integration and the rapid development of the modern logistical technology, it requires that multimodal transportation meets the needs of the supply chain integration. Therefore, research of multimodal transportation process can promote the development of multimodal transportation, achieve the logistics service aim that timely, accurate, safe and rapid, serve the best. Multimodal transportation process is a inter-organizational processe. Boundaries in enterprise-to-enterprise and organization-to-organization are faint. The various boundaries are in the dynamic changes. Collaborative processes distribute in various enterprises and organizations, change frequently that brings complexities into multimodal transportation process management . To enable the multimodal system running efficiently, realize the processes integration, and facilitate the inter-organizational processes operation smoothly, it's urgent to study the multimodal transportation process, research and develop the key technologies under the conditions of modern logistics, such as the multimodal process optimization technology and the transportation information integration technology, apply these technologies into the related enterprises, develop the transportion network that the various models of transportation dovetail closely, enhance the operational efficiency of multimodal transportation, and standardize multimodal transportion operation process. Consequently, it promotes across regions and industries operate resources in multimodal logistics enterprises for optimum allocation and integration effectively, makes the modern integrated logistics which use the multimodal transportion as the main carrier diversified, systematic and rational, drives modern logistics rapid developed.By studying the multimodal transportation process, integrating the information flow and material flow of the multimodal transportation, that can realize information sharing among the enterprises. Establish the information-sharing model which based on Web and realize the immediate call to meet the productive needs. This paper researches for the multimodal transportation process by Petri net technology. Based on a specific analysis of multimodal transportation system and subsystem, takes a certain shipping company as an example, builts a Petri modal of Rail-Sea multimodal, analyzes the modal's mathematical characteristics and simulates the multimodal flow. Researches the logistics information development, share,coordination under the multimodal condition, brings forward frameworks, methods and models of the flexible information platform. The framework with the component structure achieves the integration of logistics information. Takes multimodal transportation as the theme, eatablish a data warehouse system which sets information about the mode of transportation, carrying tools and intermediate process for the integration. And build a data warehouse which is taken the typical container depots as an example, then do the on-line analysis. Builds BPEL4WS model, analyzes multimodal business process based on Web-services and constructs the Petri-net model which Web-based to realize the process calling.Studying on the multimodal transportation system, analyzing the multimodal transportation process and utilizing the process reengineering to improve system operation efficiency. The paper researches of the multimodal transportation system model based on Petri-net, analyzes the multimodal transport system and its subsystems in details, describes the relationship between multimodal transport system with its subsystems,corresponding processes and Petri nets processes. Such as the multimodal transportation process, Petri nets process, subsystem processes involved rail, road, sea, air transportation in multimodal transportation, and the supporting subsystem process about the Customs inspection and the cargo station or others. Takes the Rail-Sea multimodal transportation as an example, builds a Petri nets model, analyzes the operation process and furtherly describes typical export processes involved booking, seaborne export, railway export, customs procedures, etc. Models for the typical multimodal transportation process by selecting Colored Petri-net based on time, structures correlation matrix to caculate S_invariant, and certifies relevant mathematical characteristics of this model. It is demonstrated that the sub-processes t2, t3 and t4 are basic subnet, each subnet is bounded, live, accessible, and the performance of large-scale multimodal transportation business process model which is composed of basic subnets is maintained, the entire network is bounded and live. Then the model is simulated and analyzed by ExSpect software that is based on the timed, colored and layered Petri-net.Aiming at the problems in the multimodal transportation process, optimized measures are raised on the basis of simulation. These measures are used to improve the cooperation between modes of transportation and efficiency of the transmission of documentation and information, reengineer the processes, and so on. Then structures an optimized Rain-Sea multimodal Petri nets, validates relevant mathematical characteristics. It proves that the sub-processes are basic subnets, each subnet is bounded, live, and accessible. The performance of the multimodal transportation business process model is maintained, and the entire network is bounded and live. Flowing time has been reduced and the efficiency of multimodal transportation process which has been optimized has been improved through the mathematical analysis, simulation and optimization.Reengineering is to transform the traditional transport using information technology. The greatest character of the process optimized is that the information can flow efficiently, orderly and accessibly. The multimodal transportation logistics information integration structure and the multimodal transportation information integration functional structure are designed, according to the characteristics of the multimodal transportation supply chain. The multimodal transportation logistics information integration structure is consisted of the foundation layer, the application-basis layer and application layer. The functional structure is consisted of the built-in functions, user-oriented services and user platforms. The multimodal transportation information integration builds the two structures and processes multi-level data, includs multimodal transportation logistics information integration and enterprise information integration. Establishes the multimodal transportation information integration platform structure and designs functional modules including logistics business management system, e-commerce logistics system, customer service system, and logistics decision support subsystem. Information integration platform structure is constituted into many layers, such as platform layer, platform control and coordination layer, business management platform layer and business management platform layer. Constructs the service-oriented integration structure of multimodal transportation enterprises, shows the integrated contents including multimodal transportation logistics enterprise data integration, process integration and personnel integration. Design an information integration framework and a closed joint-Business Intelligence (BI) structure for multimodal transportation logistics enterprises. The flexible information platform framework with the structures, methods and models are given to realize the information technology integration. Researches on logistics information development, sharing and coordination technology under the multimodal transportation condition. It lays a solid foundation of information management for calling each other of the Web-based multimodal Petri-net model.The basic data management is the basic operating environment of information technology, and the data warehouse technology is the effective tools of basic data management. The study on multimodal transportation data warehouse technology is used to establish a data warehouse system collecting transport modes, transport equipments and intermediate processes, takes the multimodal transportation as the theme. Combines with the system it analyzes the data of the typical enterprise data warehouse. Builds a multimodal transportation data warehouse which contains planning analysis phase and design implementation phase. The planning analysis phase mainly does requirements analysis, framework design, conceptual model, logical model design, physical model and metadata design. The design implementation phase designs the structure and levels of multimodal transportation data warehouse, describes its function, analyzes the modes of data loading and extraction, structures its data storage levels, and sets up the multimodal transportation data warehouse. The multimodal transportation data warehouse is established by taking the container freight station as an example. According to the characteristics of the station impliments requirements analysis for metadata and data mart(数据集市), designs conceptual structure, logical structure and data mart framework for its database. Builds a star snowflake-shaped model for the statin, that transfers data, establishes a multidimensional data set, analyzes the data of the data warehouse based on the container freight station by slicing and drilling, displayes by Excel on the client, analyzes on-line and mines data, that can fully reflects the information of the multimodal transportation cargo flux, the flow direction, the flow time etc.BPEL4WS model is established by combining with characteristics of the structure and the flow analysis based under Web-service. Analysis of multimodal transportation business process based on Web-service mainly includes intermodal business process design, information flow integration and transfer process analysis of the multimodal transportation information. Takes a typical multimodal transportation process as an example, analyzes the collaboration on Web service and information operation. Multimodal transportation collaboration process under Web-service is represented. The process which is Web-based describes and analyzed the course that Rail-Sea multimodal participant collaborates business. By using WSDL, Web-based collaboration of the multimodal transportation process appoints the operation that should do in the business process and describes Web-services provided by business processes. Those services mainly include definition of Web-service portal data type, information, Web-services portal type and link types of service in multimodal business process. Using BPEL4WS to define the multimodal transportation process, including defining the participants, the variables, incidents handling and process execution etc. Using BPEL engine to create a BPEL4WS file of multimodal transportation Web-service process. Petri net model of multimodal transportation Web-service flow is built by the conversion between BPEL4WS and the Petri net of multimodal transportation, to implement its simulation and optimization.With the support of underlying data in the multimodal transportation data warehouse, applies the multimodal transportation information integration technology and integration technology based on BPEL4WS, to realize the Calling and optimization of typical flow from the macro to micro. That effectively integrates information and improves the cost-effectiveness of multimodal transport. The information world where the technology is highly developing, multimodal transportation BPR based on information technology is the core content of the research on multimodal process optimization in the paper. The research on the optimization technology of multimodal transportation process based on Web-services has important theoretical and practical significance.