Explicit relation types

Updated: May 8, 2026

An explicit relation type connects two asset types directly together. Previously, explicit relation types were referred to simply as relation types, a naming convention still used in the classic user interface. The latest user interface uses the term "explicit relation types" to distinguish them from the newly introduced "derived relation types".

You can create, edit, and delete explicit relation types (ERTs).

Common prerequisites

You have a global role with the Product Rights > System administration global permission.

Create an ERT

You can create an explicit relation type if the out-of-the-box explicit relation types don't meet your needs.

1. On the main toolbar, click → Settings.
   The Settings page opens.
2. In the Operating model section, click Relation types.
3. On the Relation types page, click Add explicit relation type.
   The Create explicit relation type dialog box appears.
   
4. Enter the required information.

   Field	Description
   Role	Direction of the relation type going from the head asset to the tail asset.
   Head	Asset type of assets that can be the head of the relation.
   Tail	Asset type of assets that can be the tail of the relation.
   Co-role	Direction of the relation type going from the tail asset to the head asset.
   Description (optional)	Description for the relation type.

   Note The combination of a relation type's head, tail, role, and co-role must be globally unique.

5. Click Create.
   The explicit relation type is created. You can now assign it to an asset type.

Edit an ERT

You can edit an explicit relation type by changing its role, co-role, or description. The combination of the relation type's head, tail, role, and co-role must be globally unique.

1. On the main toolbar, click → Settings.
   The Settings page opens.
2. In the Operating model section, click Relation types.
3. On the Relation types page, in the Role or Co-role column of the relation type, double-click the current value, edit it, and click .
   Your changes are saved.
   

Delete an ERT

You can delete a custom explicit relation type if it isn't used in any derived relation type.

1. On the main toolbar, click → Settings.
   The Settings page opens.
2. In the Operating model section, click Relation types.
3. On the Relation types page, in the Actions column of the explicit relation type, click .
   Tip You can use the Kind column to filter the table by the relation kind Explicit.
4. In the Delete this explicit relation type dialog box, click Delete.
   The explicit relation type is deleted.