Centralized logistics system, including goods, inventory management, vehicle scheduling, distribution, transport and other links. Distribution system ultimate goal is to reduce the total cost of distribution to get "the third profit." Among them, the distribution, the optimization is a key logistics and distribution system optimization.
With the rapid development of modern logistics industry, logistics, rapid increase in the amount of information on the distribution system requirements are higher. The traditional management of the information distribution system low level, the lack of visibility; of massive data analysis, processing and decision support poor schools; In addition, the decision-making distribution model rely too idealistic and less practical factors to consider change, but in reality is poor. Therefore, improving the distribution system of scientific decision-making, visibility and level of information is necessary, and GIS integration and logistics systems are able to better achieve this goal.
This paper we use ESRI GIS software released Arc/Info9, control type MapObjects GIS systems and object-oriented programming tools, VB6.0 form development environment, GIS and logistics system to achieve integration.
A geographic information system (GIS) structure and characteristics of
Geographic Information System (GIS) is a can capture, store, manage, query, simulation and analysis of geographic information, computer systems, are all integrated geographic data processing and analysis of a large number of general-purpose geographic information technology. It is in accordance with the geographical features of the association, will be a wide range of data to link the different levels constitute a real world model, the use of space in this model to manage query and spatial analysis, and spatial information through the simulation and analysis software package for spatial information processing, regeneration, for the analysis of spatial decision-making basis.
The main components of GIS database and data management systems, spatial data processing, spatial data analysis, planning, management and decision-making models, information display and graphics output, etc. The main features include spatial and attribute data collection, editing, data processing, storage and organization, spatial query and analysis, and digital map information for display and output.
And compared to the general management information system, GIS has the following characteristics: (1) efficient storage and organization of spatial data models, spatial data and attribute data to achieve the unity of management; (2) digital map data visualization, visual and strong interaction; (3) a strong spatial data processing and analysis capabilities, a unique policy-making functions of spatial analysis.
ArcGIS is ESRI's professional GIS software release, since its inception, has maintained the world's No. 1 market share. The latest component-based GIS software Arc/Info9. In addition to the above general GIS mapping, edit, query, statistics and other basic functions, ArcGIS also provides a more robust GIS analysis functions, such as network analysis, topology analysis, overlay analysis, which includes the best path network analysis analysis, vehicle tracking trajectory analysis section. ArcGIS software is a good system of open, also uses industry-standard Com architecture with other systems for true seamless integration.
2 GIS in Logistics Distribution System
Logistics activities as the movement of objects in space, is a collection of time and space. Therefore, space-related geographic information system (GIS) have the useless. GIS is mainly used in logistics and distribution part of the powerful use of GIS spatial data analysis capabilities to improve logistics, the role of performance in dealing with issues related to spatial analysis, retrieval, processing and decision-making. For example: Visualization of logistics, distribution center location, delivery point of distribution, the best distribution route choice decision-making, logistics and distribution of dynamic monitoring, and so on.
The distribution system is, GIS technology integration, make it easier to handle logistics and distribution of goods, transportation, storage, handling, transport and other links, and distribution systems in the transport route choice, the choice of storage location, warehouse capacity to set reasonable handling strategy, transport vehicle scheduling and choice of delivery routes for effective management and decision analysis.
According to foreign practice of logistics development, GIS-based integrated logistics and distribution system is the inevitable direction of modern logistics. But now, the GIS technology into the logistics and distribution system decision-making process to achieve when there are still many technical difficulties. Main features:
(1) early geographical space, property and updating the data collection difficulties. Include a variety of factors and quantitative data such as real-time traffic updates and so on.
(2) GIS spatial analysis and integrated delivery model. More traditional model of the ideal model of the plan or network, but ignored the optimal distribution of geospatial data on the enormous impact of the ideal model of how to convert the traditional close to the actual model, and with the combination of GIS spatial analysis function, is most in need solution.
(3) computer program to provide evaluation of the optimal decision. As the evaluation standards are different, often appear to analyze the optimal result is not the result we want, how the optimality of the computer analysis to evaluate and make people's subjective experience with the combination, is the current encounter a difficult problem.
3, the distribution system based on ArcGIS integration framework and function modules
3.1 The basic ideas and the integration of systems integration framework map
Basic idea of system integration is the use of GIS component technology, ArcGIS software, and logistics are closely related to the introduction of GIS components to the traditional logistics management information platform to. Specifically, the first of the collection of geospatial data and logistics information data integration; once again the basis of the GIS component of the data display, analysis, completion of distribution network planning; and then combine orders data, and GIS in the network analysis functional integration, complete vehicle scheduling and delivery route optimization; further direction is to integrate GPS and the internet came to realize GIS logistics and distribution of real-time monitoring and networking.
3.2 System integration module
According to the basic ideas of system integration and system integration framework, integrated functional modules mainly as follows:
3.2.1 Data Acquisition and conversion modules.
Provides digital maps and editing capabilities, support multiple types of format conversion of map data and models, such as paper maps into digital GIS to identify the digital map, remote sensing data transfer, and to provide maps of spatial data and attribute data editing;
3.2.2 Database management module.
Use relational database, combined with a special spatial data model, spatial and attribute data storage management unified, integrated system is one of the key modules.
3.2.3 electronic map display module.
Achieved by the input data or database table data generated electronic map, and the distribution network and the network layer all the elements of an integrated display. Required not only to show all elements of the map can also be based on user needs, for hierarchical display, and output a variety of thematic maps, all kinds of statistical charts, graphs and data.
3.2.4 Query statistics module.
① provide property - the logical query of space and space - the property search function space elements. Can query the database, but also directly on the map to query.
② provide space for elements of statistical functions. Including its quantity, distance, area, density, traffic, etc.,.
③ providing customer orders and goods location query, combined with GPS functions and webgis features to provide customers with online inquiries.
3.2.5 GIS spatial analysis module.
Logistics operations to support the analysis of geospatial data, such as multi-layer overlay analysis, map data and attribute data, joint analysis, path analysis, dynamic analysis, monitoring, and can provide statistical analysis of the corresponding thematic map.
3.2.6 Distribution Network Planning Decision module.
The module is specifically set up for the distribution system characteristics, its decision support capabilities in the following areas:
1, the location of distribution centers and logistics network layout decisions. Distribution center is used to determine the location of planning the location of one or more facilities or existing facilities to increase point of distribution, making the total cost is minimized.
2, optimal path selection.
Optimal route selection in the logistics distribution network used to solve the shortest path between two nodes in question and the best travel Alternatives. Among them, the shortest path problem can be transformed into the fastest path problem, minimum cost, etc.; Lieutenant Colonel common logistics nodes required to solve the problem the best tour starting from the distribution center in the middle of traversing a specified number of distribution nodes and up to the end of the most good path.
3, network flow analysis and distribution zoning plan.
Between the number of distribution centers to resolve service delivery problems and the regional network of logistics division of the amount of balance. Demand for reasonable distribution center division of the scope of services, determine the radius of its supply, to achieve macroeconomic balance supply and demand, and distribution system according to the existing distribution and customer orders for goods distribution, identify potential customers, further expanding the market.
3.2.7 Monitoring and distribution logistics Evaluation.
Distribution of vehicles by GPS for real-time monitoring and scheduling, and to the completion of the distribution analysis, evaluation, also requires customers to provide the goods needed to locate online query.
4 key technology to realize the system
System integration technology lies two things: data integration and functional integration. Data integration mainly refers to the integration of heterogeneous data; functional integration are based mainly on logistics and distribution needs of the system of electronic map display and integrated development policy-making function.
4.1 Data Integration
4.1.1 Geographic Data Acquisition and Processing.
Data collection, including spatial data and attribute data of two parts, spatial data also include the geometry of geographic data and topology data. GIS-based logistics system will be the actual logistics and distribution network in the distribution center, delivery path elements were abstracted as point, line elements, the links between elements of the abstract for the topology. Spatial data collection into the digital map, remote sensing data acquisition and GPS data collection in three parts. Which depends mainly on the digital map data in vector scan to complete.
Spatial data processing used mainly on the traffic data and node data topology check to ensure connectivity between all nodes. Attribute data processing, including the right of the road data value node assignment and the distribution parameters of the logistics area assignment. The data processing can be completed ArcMap ArcGIS platform.
4.1.2 unified spatial and attribute data storage management.
GIS-based integrated logistics system is one of the key problems of heterogeneous data processing. The unification of spatial data and attribute data stored in relational database management system, to realize non-spatial data, spatial data integration and seamless integration. The more mature the system chosen ESRI's ArcSDE spatial data model to spatial data and attribute data of unified management, spatial data and attribute data stored in relational database SQL Server 2000, by ArcSDE for spatial data management and access, through internal MapObjects client for data maintenance, analysis and supporting planning.
In addition, during storage, display, query and analysis, spatial data and attribute the association between, you can achieve through geocoding. Moreover, the map data should be stratified management, such as free distribution of electronic map as a basis for the regional base map, and distribution agency distribution map of the region as a business management layer.
4.2 Functional integration
4.2.1 electronic map display.
MapObject (MO) can achieve most of the GIS functions, map display can be achieved by. Arc / Info also offers a number of special Sichuan Ocx controls, controls related to graphics are ESRI DemoMc.Ocx.
4.2.2 Network Analysis.
Network analysis function is in fact custom development platform will network analysis of efficient algorithms and integration of GIS spatial analysis and calculation functions to generate a new group, and all the logistics system to call the component can be a powerful network analysis function.
ArcInfo core module provides a strong analysis capabilities, including network analysis, topology analysis, overlay analysis. But the pertinence and large upfront investment. Secondary development platform MapObject addition to supporting the basic functions of GIS, it also provides a small amount of simple GIS spatial analysis function, but the logistics and distribution network analysis complicated, and the system comes with an idealized model of network analysis, real-time differential, algorithm space large, slow to solve. Therefore, the need for the secondary development of a powerful network analysis MapObject custom features. We choose to develop in the VB environment.
Secondary development of three key issues: first, the choice of network analysis algorithms. Algorithm will have a direct impact on the efficiency of network analysis, widely recognized as the shortest path analysis can be used better Dijkstra algorithm and Floyd algorithm; one to many distribution routing problem more heuristic algorithms, such as savings, sweep method and so on. The second is the network nodes and weight factors to determine the right path. When determining the weights, the network needs to be different dimensional factors (such as traffic information, etc.) to quantify, may be graded according to experience rate for horizontal comparison. Third, the number of constrained multi-objective network analysis, the need to determine and compare each path, and to determine the actual weight coefficient of each target. Weight coefficient is not the same time, the "optimal" standard methods.
5 Conclusion
In this paper the general principles of GIS application systems development and logistics and distribution system with actual reality, the first analysis of logistics systems and their characteristics, and GIS GIS applied to logistics and distribution are summarized the main issues; then proposed logistics distribution system based on ArcGIS integration initial solution, that the integration of GIS and logistics must first solve the first two key issues: how to collect useful data and the actual organization of its stores, one is how to set up close to the actual distribution optimization model and algorithm integration achieved. Of course, further speaking, GPS positioning and webgis integrated development is the key to integration, which is the focus of our next work.