Define tiers

Tiers are used to organize subnetworks into groups within a domain network. A domain network is composed of one or more tiers forming either a hierarchy of tiers or partitioned groups of tiers. A single tier defines a collection of individual subnetworks that all have the same subnetwork definition.

The Add Tier tool is used to define a tier within a domain network.


To define a tier, the following requirements must be met:

  • The network topology must be disabled.
  • The name of the tier must be unique within the domain network.
  • When working with an enterprise geodatabase, ensure the following:
  • The network classes must be empty.

    It is important to perform all of the network configuration before appending data to the network classes. The Add Tier tool creates a subnetwork name field with a nonnullable property to the underlying network feature classes and tables. This add field process can only be completed if the network feature classes and tables are empty.

Define a tier

To define a tier, complete the following steps:

  1. On the Analysis tab, in the Geoprocessing group, click Tools Tools to open the Geoprocessing pane.
  2. In the Geoprocessing pane, search for and select Add Tier.
  3. For the Input Utility Network parameter, choose a utility network.
  4. For the Domain Network parameter, choose the domain network.
  5. For hierarchical domain networks, provide an existing Tier Group Name.

    If the domain network does not have a Tier Group, use the Add Tier Group tool as a prerequisite.

  6. For the Name parameter, specify a tier name.

    The name must be a unique tier name within the entire utility network and cannot exceed 64 characters. The following special characters are invalid:

    • Grave accent (`)
    • Tilde (~)
    • At sign (@)
    • Dollar sign ($)
    • Percent sign (%)
    • Caret (^)
    • Asterisk (*)
    • Plus sign (+)
    • Equal sign (=)
    • Vertical bar (|)
    • Backslash (\)
    • Open-angle bracket (<)
    • Close-angle bracket (>)
    • Question mark (?)
    • Open brace ({)
    • Close brace (})
    • Period (.)
    • Exclamation point (!)
    • Single quotation mark (')
    • Open bracket ([)
    • Close bracket (])
    • Semicolon (;)
    • Carriage return (\r)
    • New line (\n)
    • Double colon (::)

  7. Provide a rank for the tier in the Rank parameter.
  8. Specify a type for the Topology Type parameter.

    Choices are determined by the tier definition for the domain network. Hierarchical domain networks are automatically assigned a Mesh topology type, while partitioned networks can be assigned Mesh or Radial.

    Learn more about the topology type for a tier

  9. For hierarchical domain networks, provide a field value for Subnetwork Field Name.

    When adding the initial tier group and tiers for the domain network, provide a new subnetwork field name to add for each domain network feature class and table. When the domain network contains multiple tier groups, existing subnetwork name fields can be reused when adding tiers that represent the same logical aggregation of a subsystem of the domain. If using an existing field, the field must be one that was previously added via the Add Tier tool itself. This field exists within all domain network classes with the following specifications:

    Type: esriFieldTypeString
    IsNullable: VARIANT_FALSE
    DomainFixed: VARIANT_FALSE
    Length: 2000
    IsIndexed: true
    IsUniqueIndex: false
    IsEditable: VARIANT_FALSE
    Default value: "Unknown"
  10. Click Run.

The specified domain network now has a new tier. To view the new tier definition, open the network properties for the utility network.

Next, set the subnetwork definition for the tier.