View source for Merge External Model

A merge external model operation imports nodes from an external model file into the current project. During this process, the system checks each incoming node’s globally unique identifier (GUID):

* If the node’s ID does not already exist in the current project, the node is eligible to be added.
* If the node’s ID is already present, the existing node in the project is preserved and the incoming one is ignored.

The merge also verifies that each incoming node has a valid parent in the destination project. Any node that cannot be placed under an appropriate parent - even if it would otherwise qualify for merging - is excluded to maintain structural consistency.  In order for a parent to be considered valid, the user must have (at least) write permissions (to the parent node) and the parent node must not be [[Projects and Models Management#Model Versions | published]].

== Overwrite Option ==
If the Overwrite option is enabled, the merge behaves more aggressively. For nodes that exist in both the source model and the destination project, the system compares their contents. When differences are found, the destination node is updated to match the version from the source model.

== Check for Name Collisions Option ==
The Check for Name Collisions option controls how the merge process handles situations where two different entities - identified by different GUIDs - share the same name.

When '''enabled''', the merge operation will fail if it encounters two distinct entities that use the same name. This safeguard ensures that no ambiguous or conflicting names are introduced into the project. (Entities with the same GUID and same name are not affected by this rule.)

When '''disabled''', the merge operation will complete even if name conflicts exist. In this mode, the system allows potentially overlapping names to coexist, and any required name adjustments must be resolved manually after the merge. 

This setting is recommended when merging models from unrelated or independently developed sources, where naming overlaps are more likely.