Location Allocation

Feature Description

Location Allocation selects optimal locations from multiple candidates based on specified parameters. This analysis provides references for facility site selection. For more details, see the Location Allocation Overview page.

Steps

  1. Open the required network dataset for analysis.
  2. In the "Transport Analysis" Tab's "Route Analysis" group, check the "Environment Settings" checkbox to open the "Environment Settings" window. Configure basic network analysis parameters (e.g., weight field, node/edge ID field), analysis result parameters, and trace analysis parameters (for trace analysis only). For details, see the Network Analysis Environment Settings Window.
  3. Create a Location Allocation instance. In the "Transport Analysis" Tab's "Route Analysis" group, click the gallery drop-down button and select "Location Allocation". The Instance Manager window will appear automatically, and the cursor will switch to drawing mode to add center points.
  4. Add center points to the current network layer. Center points (resource supply centers) are facilities providing resources/services. Two methods are available:
    • Add by Mouse

      Click the "Add by Mouse" button in the Instance Manager toolbar. Click on the map to add points, which will be listed in the Instance Manager. Right-click to finish. Note: Ensure proper node tolerance is set. Clicks beyond this range may fail.

    • Import Centers

      Import point datasets from the current workspace as center points. Right-click the "Centers" node in the Instance Manager and select "Manage Center Stop". Use the import command in the dialog. For details, see the Manage Center Stop window.

      Note: To delete a center, select it and choose "Remove" from the context menu or press Delete.

  5. Click the "Parameter Settings" button in the Instance Manager to open the "Location-Allocation Parameter Settings" dialog:
    • Parameter Settings

      Expected Number of Centers: The desired number of optimal locations in results. Cannot exceed fixed centers count if present. Requires fully connected networks.

      Least Center Mode: When checked, calculates the minimum number of centers needed for full coverage. The expected centers setting becomes invalid. Analysis fails if full coverage is impossible.

      Failure causes: 1) Non-connected networks (check via flow direction analysis); 2) Insufficient center quantity/weight values.

      Allocate from Center: When checked, allocation flows from centers to demand points. Otherwise, reversed.

    • Result Settings

      Datasources: Select datasources to store results.

      Allocation Point Dataset: Saves allocation centers as point datasets. Attributes include:

      Field Description
      CenterID Node ID of allocation point
      SupplyCenterType 1=Center; 2=Fixed center
      DemandCount Resource quantity
      TotalWeights Total cost to all served nodes
      AverageWeight Average cost per node
      MaxWeight Maximum resistance value

      Demand Point Dataset: Saves demand points with attributes:

      Field Description
      CenterID -1 indicates non-demand point
      Cost Path cost (-1 for non-demand points)

      Click "OK" to confirm settings.

       

  6. After configuration, click "Execute" in the Route Analysis group or Instance Manager to run analysis. Results display immediately and can be saved as datasets.
Caution:
  • Center types must be Center or Fixed Center.
  • Center points must be on network nodes.
  • Barrier points set in network layers can be managed via the Network Analysis Manager. See Barrier Management.

Related Topics

Location Allocation Overview