Find Nearest Facility

The nearest facility analysis refers to finding one or more facility points with minimum cost for each event point given a set of event points and a set of facility points in the network. Show Results Optimal Path Analysis, cost and driving direction from event point to facility point (or from facility point to event point). At the same time, you can also set the search threshold, that is, the search range. Once the search range is exceeded, the search will not be performed again.

• Facility point: the basic elements of the recent facility analysis, such as schools, supermarkets, gas stations and other service facilities.
• Incident Point: An essential element of the recent facility analysis, the location of the incident that requires the service to be provided by the facility point.

Search for the nearest facility point in Network Analysis is mainly used for similar events such as finding the nearest gas station due to insufficient vehicle fuel and finding the nearest emergency center due to sudden illness. For example, if the incident point is the scene of a traffic accident, it is required to find the nearest hospital that can be reached within 10 minutes, and those that can be reached in more than 10 minutes will not be considered. In this case, the accident point is an event point, and the surrounding hospitals are all facility points. Finding facility points is actually a kind of path analysis. Therefore, obstacle edges and obstacle points can also be set. When there are obstacles on the driving route, it will be impossible to pass. These situations need to be considered in the analysis process.

Application example

Knowing that there are multiple gas stations and the location of a truck in an urban area, the truck needs to find a gas station that can be reached within 20 minutes to fill up as soon as possible without delaying the delivery journey. Take the nearest gas station search as an example to explain the steps of Find Nearest Facility:

1. Set the Network AnalysisBasic Parameters to set the forward/reverse weight Field Settings to the time field.
2. Import refueling stations as facility points.
3. The truck location is imported as an event point.
4. Set "Event-> Facility" in the Find Nearest Facility direction; the truck needs less than 20 minutes to reach the gas station, so the search radius is set to 20; set the number of facility points to 1.
5. Specify Result Dataset, Execute Analysis, and View Analyst Result.

As shown in the figure below, it is the result of finding the nearest facility. If there are 9 gas stations around the truck, the route of the truck to the nearest gas station obtained by the final analysis is shown as the green line in the figure below.

Operating instructions

1. Open the Network Dataset for analysis.
2. Select the Environment Settings check box on the Traffic Analysis tab-> Road Network Analysis group-> to display the Environment Settings window. Set Network AnalysisBasic Parameters (such as Weight Field, node/Edge ID Field, etc.) In this window. Analyst Result parameters and parameters for tracking analysis (Facility Network Analysis needs to be set). For an introduction to the Environment Settings window, see Network AnalysisEn vironment Settings window Page.
3. Creates a new instance of the Find Nearest Facility. On the Traffic Analysis tab-> Road Network Analysis group-> click the Galley Drop-down Button-> select Find Nearest Facility. After the instance is successfully created, the Instance Management window automatically pops up. For an introduction to the Instance Management window, see the Instance Management window page.
4. Adds an event point to the current Network Data layer. There are two ways to add event points. One is to click the mouse in the Network Data layer to complete the addition of sites; The other method is to import the point data. The point object in the Point Dataset is imported as the event point. Please refer to the description on the Add site page for specific operations. Only one event point can be added to

   a Find Nearest Facility instance. After adding one event point, the mouse status will automatically switch to the status of adding "facility point". Note: The appropriate Node Tolerance needs to be set. If the mouse click position exceeds the Node Tolerance, the site addition may fail.

5. Add facility points and obstacle points in the network layer in the same way. After adding, right-click to end the operation. Barrier point management can be found on the barrier point management page.

   Note: When the Application performs Find Nearest Facility, the Analyst Result is not related to the order of the imported facility points. To delete a facility point, select the "Facility Point" directory node, and select "Remove" in the pop-up Context Menu, or select the facility point to be deleted and press the Delete key.

6. Click Parameter Settings "in the Network Analysis Instance Management window to pop up the Find Nearest Facility Settings dialog box. Set the Find Nearest Facility Analysis Parameters.
   • Search Settings

     Find Direction: Specify the direction to find the nearest facility point, from the event point to the facility point or from the facility point to the event point. Different search directions have an impact on Analyst Result. For example, it takes 15 minutes to travel from the event point to the facility point, and 20 minutes to travel in the opposite direction.

     Search Radius: Maximum search radius. Find the nearest facility point by using the event point as the center and the entered radius as the search range. Once the facility point meeting the conditions is found or the search radius is exceeded, the search will be stopped. The radius is in the same units as the Weight Field in the Network Analysis environment. If you want to find the entire network, set the value to 0.

     Number of facility points: the number of facility points closest to the event point that are expected to be found. For example, in the event of a disaster, it is necessary to send the injured to one or more nearest hospitals for treatment.

   • Result Settings

     Save node information: Select whether to save all node information from the event point to the facility point (or from the facility point to the event point) in the Analyst Result. If Save Node Information is selected, save the node as a Point Dataset and give it a name. The Dataset will be saved under the Datasource where the Network Dataset is located. The field NodeID represents the Node ID of the facility point passed by the Analyst Result, and the field RouteID represents the routing line identifier from the event point to the facility point (facility point) in the Analyst Result.

     Save Arc Segment Information: Select whether to save all arc segment information from the event point to the facility point (or from the facility point to the event point) in the Analyst Result. If the Save Arc Segment Information check box is selected, it is saved as a Line Dataset with a name, and the Dataset is saved to the Datasource where the Network Dataset is located. The EdgeID field represents the identifier of the routing line from the analyzed event point to the facility point (facility point to event point).

     Enable Path Guide: Select whether to generate Driving Guidance during analysis. Driving Guidance records the path information in the Transportation Analysis result. A Driving Guidance object corresponds to a driving route from the start point to the end point. When the Enable Path Guide "checkbox is checked, it indicates the path information of the Output Analysis Results in the Driving Guidance window. For an introduction to Driving Guidance, see the Driving Guidance page.

7. When all Parameter Settings are complete, click the Execute button in the Road Network Analysis group on the Traffic Analysis tab or the Execute button on the Instance Management window. Operation complete. The Analyst Result is displayed immediately in the Map. Analyst Results can be Save as Dataset for use elsewhere.

Precautions

• For facility point and event point information, it can be exported to Point Dataset for direct import and use in similar analysis in the future.
• The facility points and event points may be on network arcs and network nodes or nearby areas within capture tolerances.
• If obstructing points are set in a Network Analysis layer, the obstructing point information is displayed in the Network Analysis management window, and the obstructing points can be managed in this window. Refer to the Barrier point management for instructions on how to add obstacle points.
• Due to the influence of the search radius, the number of found facility points is not always equal to the number of found facility points (it may be less than).