Which is the best approach/steps to delete old information from Demand Management?(Customers, Items)

Summary:

Hi Customer Connect Community,

Which is the best approach/steps to delete old information from Demand Management?(Customers, Items) As per previous discussions (see reference question below) I would say:

• Purge Customer Information via 'Purge Data Repository' by selecting Source System and Purge Global Entities as Yes. Reference Data: Customers.
• Import Item information via target collection: File Import and Export> Load Planning data from file (This confuses me since in documentation Items is not a Global Entity but I'm able to see items as Reference Data in the 'Purge Data Repository')
• Import Shipment History information via target collection: File Import and Export> Load Planning data from file