ArcGIS Utility Network

Utility Network Error Management: Topology Errors


In the years since we’ve released the ArcGIS Utility Network we’ve discovered that a handful of different topology errors account for the majority of errors that our users experience on a daily basis. We’ve greatly expanded our online documentation on this topic to include all of the errors along with the approaches for resolving them.  However, because these errors and their resolutions are specific to different industries we’ve decided to develop this blog that provides examples and screenshots for all of these major issues and their corresponding solutions.

By reading this article you will be better equipped to understand how to interpret these errors and what techniques you can apply to the decision-making process for resolving them.  We continue to improve the error management and quality assurance experience and hope that this series of content will go a long way to improving your daily experience.

There are a disclaimers with the content you will find in these articles:

Industry Specific Examples

Check out one of the following blog posts for industry specific examples of how to identify and resolve errors.

Cheat Sheet

Below you can find a table that can be used as a quick reference for the most common types of topology errors customers encounter with their data.  You can download a printer-friendly version of this table from the Utility Network Community on the Esri Community page.  Feel free to save a copy of it and refer back to it often!

Error Type Error Description Resolutions
Junction-Edge Errors 8: Invalid connectivity – No junction edge rule
  1. If you determine that one of the features has an incorrect asset group / asset type or the features have not been drawn correctly than you should fix the incorrect data.
  2. If the affected features have been drawn correctly and should be allowed to connect then your geodatabase administrator can add a rule to your network to allow them to connect.
Ambiguous Connectivity 9: Invalid connectivity – More than one junction edge rule applicable
  1. In most cases this error is caused by not populating the terminal connections for a device and line. You should first try to use the terminal connections tool to assign the terminal connections between the line and device.
  2. If the type of line that has an error can never be connected to one of the terminals or features, then you should remove the invalid rule that allows for that connection.
  3. If you have stacked junctions and/or devices that are connected to a line then you should move one of the features so they are not stacked.
Edge-Edge Errors 10: Invalid connectivity – The edges are different subtypes and cannot connect
  1. If the two features should be the same type of line then you can change the asset type on one of the lines so their asset types match.
  2. If both lines are properly classified then you will need to create a point feature between the two lines. When creating this feature you will need to make sure that the newly created point either has an edge-junction-edge rule with both the lines or it has a junction-edge rule for each individual line.
  3. If the two lines shouldn’t be connected then you should move one of the two lines so they are no longer connected.
Stacked Points 25: Stacked point features
  1. If the stacked feature appear to be duplicate features, or one of the features is invalid then you should delete one of the stacked features.
  2. If both features are valid then you will need to move one of the features so it is no longer stacked. You may need to redraw or add new lines to maintain connectivity for the area.
Invalid Terminal Connection 36: The line feature has an invalid terminal
  1. If the line is not connected to a device with terminals, you should edit the line and set the terminal attribute to None using the attributes pane
  2. If the line is connected to a device with terminals you will need to edit the line and reset the terminal attribute to None using the attributes pane before you can correct the terminal using the terminal connections tool.
Midspan Terminal Device 38: Devices with multiple terminals cannot be midspan
  1. If the device is drawn correctly then you should split the line it is connected to and use the terminal connections tool to assign the terminal connections between the line and device.
  2. If the device is not drawn correctly then you should move the device to its correct position. You may need to run the assign terminal connections tool once you’ve moved the device.

Viewing Rules

Some of the errors require that you know what network rules are configured in your database and there are several ways you can do this.  For instructions on how to review all the rules in a network read the view network rules page in the online help for instructions on how to do this.

There is also a  toolbox provided by ArcGIS Solutions that allows you to see all the rules configured for a given feature, which is convenient for troubleshooting purposes.  You can access this tool and learn more about some of the other tools provided by the ArcGIS Solutions team by reading the Utility Data Management Support blog.  I have provided an abbreviated version of the instructions for using the “Configure UN Layers” tool here, for reference purposes.

Once you have downloaded the tools and added the toolbox to your project, open the “Configure UN Layers tool”

Open Configure UN Layers
Open Configure UN Layers

Check the box next to “Rule Popup”.  By default the tool will only modify your active map in your current project, on your active map so you can leave these parameters alone if this is what you want.  It is recommended you pause your map before running this tool, since the map will refresh every time a layer is updated.

Add Rules to Current Map
Add Rules to Current Map

Once the tool finishes running you will find the list of rules for a feature at the bottom of your popup.  Feel free to modify its location or style using the configure pop-up tool.

Popup with rules
Popup with rules

Additional Resources

  1. For a full list of all the possible network errors, refer to the Error Management page in the online help.
  2. For a detailed explanation of all these errors and their resolutions, refer to the Fantastic errors and how to fix them: part 1 blog post.

About the authors

Robert Krisher is a Product Engineer with Esri who has over 15 years of experience implementing Enterprise GIS for Utilities.


Remi is the Product Manager for the ArcGIS Utility Network and spends his free time exploring the US Southwest desert and California beaches.

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