SubnetLine feature class

The SubnetLine feature class stores a set of linear features, each representing a subnetwork. The purpose of the SubnetLine feature class is to aid visualization during editing, enable generation of subnetwork maps, and output summary information about the subnetworks.

The SubnetLine feature class is a read-only, system-provided feature class that is updated internally by the running of certain utility network tools. All valid connected lines are aggregated to comprise a single feature for the subnetwork in the SubnetLine class. The lines aggregated to create the SubnetLine feature class are specified in the subnetwork definition for the tier using the Aggregated Lines for SubnetLine Feature Class parameter. These aggregated lines are a subset of the Valid Lines defined for the tier. Since associations are not represented in the SubnetLine feature class, a subnetwork can be represented as multipart.

The SubnetLine feature class is updated by the following operations:

  • The Tier name attribute field is defined as the subtype field for the SubnetLine feature class. For each tier that is added to a domain network using the Add Tier geoprocessing tool, an additional subtype code and description pair are added for the subtype.
  • Each time the Update Subnetwork tool is run against a dirty subnetwork, a corresponding row is created, updated, or deleted in the SubnetLine feature class. The following are examples of changes made to the SubnetLine feature class during Update Subnetwork:
    • A row is added when you create a subnetwork.
    • An existing row is updated when changes are made to traversable features in a subnetwork.
    • A row is deleted when you delete a subnetwork.
    • A row can be added, updated, or deleted as changes are made to the Aggregated Lines for SubnetLine feature class parameter for the subnetwork definition.

When a named version is reconciled with the Default version, the SubnetLine class is considered. When a version is posted to Default, the SubnetLine class is not included. This is because the SubnetLine class is only valid in the version in which the subnetwork was updated. After a version has been reconciled, it may need to be validated and have the subnetwork or subnetworks updated again. Once the version is posted to Default, dirty areas are created. After validation of the network topology, performing update subnetwork in the default version updates the SubnetLine class.

To use the SubnetLine feature class as a visual aid during editing tasks, set an appropriate scale suppression; for example, do not show the layer when zoomed in closer than 1:20,000. Also, apply a meaningful symbology to distinguish the collections of your subnetworks by using the Subnetwork Name field.

Attributes in the SubnetLine class

Features from the SubnetLine class have the following attributes:

Field nameField aliasDescription

Is dirty / Status (when creating a new utility network)

Indicates whether a subnetwork is in a dirty, invalid, or clean state. To learn more, see Subnetwork status.


Tier name

Name of the tier to which the subnetwork belongs.


Subnetwork name

Name of the subnetwork the aggregated line or record is representing.


Subnetwork controller names

Names of the subnetwork controllers defining the subnetwork.


Last update subnetwork

The last time the subnetwork was updated using the Update Subnetwork tool.


Last ack export subnetwork

The last time the subnetwork was exported using the Export Subnetwork tool.

This attribute is only updated when Set export acknowledgement is set to true.

You can add additional fields to the SubnetLine feature class to contain summaries.

Summaries are an optional component of the subnetwork trace configuration that allow you to gather additional information about a subnetwork and store it in an attribute of the SubnetLine feature class. For example, you can use summaries in a gas network to communicate the Maximum Allowable Operating Pressure (MAOP) and output the total number of customer services for a pressure zone.

When summaries are present, a record is created in the class to display subnetwork and summary information even when the Aggregated Lines for SubnetLine feature class parameter is not specified as part of the subnetwork definition for the tier. This creates a record with empty geometry and may be useful when you want to summarize subnetwork information when working with nonspatial network features or situations in which multiple SubnetLine features overlap, reducing the utility of the geometry while still enabling access to summary information.