ServiceNow provides De-duplication tasks to remediate duplicate CIs that have been identified via CI Identifier rules.

Step 1 - Setup the workflow

• Create a workflow and assign it to the Reconcile Duplicate Task [reconcile_duplicate_task] table
• Make sure to publish. The exact content of the workflow doesn't matter at this point.

Step 2 - Setup the CMDB Remediation record

• In left-nav, type CMDB Remediations, click on CMDB Remediations under the Configuration application. (If you don't see it, check the modules list to see if it is inactive. It was inactive in my instance.)
• Click New
• Add a name, set Task type to "Reconcile Duplicate Task", and select the workflow you just created

Step 3 - Remediate

• In left-nav, type "De-duplication Tasks". Open the De-duplication Tasks module.
• This should provide a list view
• If tasks are present, open an active one
• Click on the Remediate button, a popup should display
• Your workflow should display in the drop down.

Step 4 - Setup and test your workflow

• Now you can finish configuring your workflow and test it on the tasks
• If you have no tasks, you may need to setup CMDB Health Dashboard rules to identify duplicates

Here is a docs site article for more information:

https://docs.servicenow.com/bundle/jakarta-servicenow-platform/page/product/configuration-management...