After loading your dataset, use the Create Clusters page to create clusters of demand locations that are served by the selected DC. Transport costing is calculated based on the clustering.
The app generates the specified number of clusters when you click the AIMMS logo button to run Auto-Clustering. The algorithm is similar to the one used for Center of Gravity. Each location served by the selected DC will be assigned a cluster.
The Center of Gravity algorithm needs an initial solution to determine the centers of gravity. By default, the Secondary Transport Costing app uses a random initial solution. Based on that solution, a clustering is calculated. Because of the randomness, the app does this 20 times and takes the best solution.
Another way to get an initial solution is by selecting clusters yourself in User Clusters.
Input for Auto-Clustering¶
In the Input for Auto-Clustering widget, select a Distribution Center (DC) and the number of clusters to calculate Secondary Transport Costing. You cannot continue without selecting a DC.
You can start with an approximate value for the number of clusters. Later, you can do a Cluster Analysis to find the best number of clusters.
When Use User Input is switched on, Auto-Clustering procedure uses the clusters selected in the User Clusters widget as starting CsoG.
The Totals widget shows the following three numbers that are based on the current clustering.
- Distance Traveled - The total distance traveled is the number of trips needed in each cluster, multiplied by the average trip distance for a cluster, summed over all clusters.
- Costs - The total cost based on the total distance, time and trip-based cost summed over all clusters.
- # Vehicles - The total number of vehicles (based on averages) that are required for the current clustering.
The Decrease/Increase Nodes widget lets you adjust the node size factor so that the visualization is useful based on your data. This is helpful, e.g., when high demand/supply nodes overlap, or several small nodes are difficult to see on the map. A node size factor of 1 means that all nodes have equal sizes.
When a node is selected in the Cluster Distribution Map, the Location Details widget shows the name of the selected location and (if available) in which cluster the location is included.
Cluster Distribution Map¶
On the Cluster Distribution Map, you can see the following information:
- DC location(s)
- Demand locations served by the selected DC (each cluster has its own color after Auto-Clustering)
- Center of gravity locations for each cluster (after Auto-Clustering)
- User clusters (if entered)
The Legend shows labels for the different node colors. If it is not visible, click the menu icon (three lines) in the bottom right corner and select Show Legend.
When you hover over a node in the map, the node is highlighted. When you click on it, it is selected. When a node is selected, all nodes in the corresponding cluster are highlighted. The corresponding cluster is also highlighted in the Legend widget and the Clusters table.
Data about the location selected in the map is shown in Location Details.
The User Clusters widget shows all the locations selected manually as User Clusters. To add locations to the list:
- Switch on Use User Input in the Input for Auto-Clustering widget.
- Select a location by clicking on its node on the map.
- Click the menu icon (three lines) in the bottom right corner and select A. The selected location appears on the User Clusters table.
- Make sure the Number of Clusters in the Input for Auto-Clustering widget matches the number you selected.
- Click the AIMMS logo button to run the Auto-Clustering procedure. The app starts with the locations you provided and then optimizes the solution.
When you click the menu icon (three lines) in the bottom right corner, other options appear.
- Show Legend
- Toggle to the Legend widget.
- Select Products
- Toggle to the Products widget. You can select which product(s) to consider in demand loads.
- Add User Cluster
- Adds a location selected in the map (and visible in the Location Details widget) to User Clusters list.
- Delete Selected User Clusters
- Deletes the user clusters that are selected in the User Clusters widget.
- Reset Map Area
- Centers the data shown in the Cluster Distribution Map.