Rules are an important component of data quality. When used in conjunction, both network rules and attribute rules help ensure data integrity during the editing process.
Network rules dictate which features can connect or associate with other types of features. These rules are imposed at the feature class level for specific asset groups and asset types (also using terminals if applicable). Network rules are stored at the utility network level, which allows features to connect and associate across different domain networks.
In a utility network features can connect and associate as long as feature restrictions are respected and network rules exist to allow such relationships. Linear features with the same Asset group and Asset type attribute can connect without a rule. Features with different Asset Group and Asset Type fields require a rule to connect.
All rules are evaluated when enabling the network topology. Association rules are also evaluated when an association is created.
The rule type indicates how features can affiliate. There are five types of network rules as follows:
- Junction-edge connectivity (geometric coincidence)
- Edge-junction-edge connectivity (geometric coincidence)
- Junction-junction connectivity associations
- Structural attachment associations
- Containment associations
Manage network rules
Rules are required by a utility network to enable the network topology. To build a rule base and allow different types of features to affiliate, you can add rules using the Add Rule and Import Rules tools. Once a rule is added to a utility network, no features can connect or associate other than those participating in that rule.
To delete a rule from a utility network, the Delete Rule tool is used. Network rules can be deleted without disconnecting features or removing associations that are using the rule. Caution should be taken when deleting rules that support existing features in a utility network. Existing features that rely on deleted rules are marked with error features when the network topology is reenabled to indicate there is no rule to support the relationship. Features with geometric coincidence are disconnected (no longer snapped) after validation or enabling the network topology.
Rules can be exported from a utility network in bulk using the Export Rules tool.
To review the existing rule base for a utility network, the Network Properties dialog box can be viewed.
There are many configuration tasks for managing rules in a utility network:
- Add connectivity rules
- Add containment association rules
- Add structural attachment association rules
- Import and Export network rules
- Delete a network rule
Since network rules are managed by accessing the Default branch version, updates to the utility network rules are not reflected in existing user versions until a reconcile operation is performed.
Connectivity rules govern the types of features that can obtain geometric coincidence connectivity or establish a connectivity association to other types of features. There are three types of connectivity rules: junction-junction association, junction-edge, and edge-junction-edge.
Connectivity rules can be established between features from the Structure network to allow for tracing; for example, a new conduit line needs to run from one location to another. A network of utility tunnels are already in place. The utility tunnels are traced to determine potential pathways for the new conduit line.
Junction-junction connectivity association rules govern the establishment of a connectivity association between two point features that are not necessarily geometrically coincident. Junction-junction connectivity association rules are created between device and junction feature classes at the asset group and asset type level—these rules build on top of existing feature restrictions for valid connectivity associations. These rules are evaluated when you attempt to establish a connectivity association. If there is no rule to support the association, an error is returned and the feature is not added to the Modify Associations pane. Imported associations are evaluated on import or when the network topology is enabled. Junction-junction rules support terminal connectivity. To delete a junction-junction connectivity rule, all existing associations using that rule must first be deleted.
Junction-edge connectivity rules are based on geometric coincidence and control the types of line features that can be connected to other types of point features. These rules build on top of existing feature restrictions for valid geometric coincidence. Junction-edge rules are evaluated when you enable or validate the network topology. During an edit operation in a proper snapping environment, features without supporting rules cannot snap together. This, however, does not prevent you from placing them somewhat coincident. When the topology is enabled or validated, these invalid cases of coincident features without rules are not connected and are instead marked with error features.
Junction-edge connectivity rules support line end connectivity to a device with terminals. Establishing a connection midspan along a line to a point with terminals requires a nonterminal point to be snapped midspan on the line while the terminal point feature is coincident with the line end. Junction-edge connectivity is established between the midspan point (for example, a tap) and the line. A junction-junction connectivity association is then established between the two point features (specifying a terminal). Analytic operations travel through the line and the tap point to the connected terminal.
Edge-junction-edge connectivity rules are based on geometric coincidence and control the types of line features that can be connected using an intermediate point feature. Edge-junction-edge connectivity rules are evaluated when you enable or validate the network topology.
The following image shows the three types of connectivity rules:
Structural attachment and containment rules
Structural attachment association rules constrain the types of features that can be attached to a given type of feature (structure). Structural attachment association rules are created between structure junction feature classes (structure) and feature classes from the device, junction, assembly, and structure junction feature classes (attachment) at the asset group and asset type level—these rules build on top of existing feature restrictions for valid structural attachment associations. An appropriate association role must be assigned prior to adding structural attachment and containment rules.
Containment association rules constrain the types of features that can be contained in a given type of feature (container). Containment association rules are created between the assembly and structure network feature classes and other network feature classes at the asset group and asset type level—these rules build on top of existing feature restrictions for valid containment associations.
Both of these types of rules are evaluated during edit operations (similar to junction-junction connectivity rules) but do not support terminals. When attempting to establish one of these associations, the respective list of rules is evaluated to confirm the association is valid. If there is no rule to support the association, an error is returned and the feature is not added to the Modify Associations pane.
When structural attachment and containment rules are imported, their respective rules are evaluated. If the network topology is disabled and the import takes place, the rules are evaluated when the network topology is enabled again. Edits made to features participating in structural attachment or containment associations are also evaluated during enabling or validating the network topology.
The following image shows the structural attachment and containment associations: