You can determine the level of freedom with which users can make parallel changes to a hierarchy that belongs to a particular hierarchy type. A change to a hierarchy can comprise adding a node, moving a node, removing a node, changing the attributes of a node, or creating a hierarchy.

After a change to a hierarchy is saved to a change request, changes to interlocked nodes must be saved to the same change request. The system determines which nodes are interlocked by referring to the Interlocking setting for the relevant hierarchy type.

You make these settings in Customizing under  Master Data Governance, Central Governance General Settings Process Modelling Hierarchies Define Scope for Changes .

Note that an Interlocking setting of Strict has a considerably greater impact on the system performance than a setting of Loose, as the amount of data records the system locks and checks is higher with a setting of Strict.