Multi Org approach allow more than One CRM Production Orgs to be connected to a single Marketing cloud instance. You will need this configuration when a Parent Organisation has more than one child company and both using Salesforce CRM products and have complete different and independent marketing automation teams and approaches.
In the figure below 2 separate companies are using same marketing cloud instance for their marketing automation needs
BU 1 is connected to CRM Production 1 and has child BU 1-1.
Account , Contact , Lead data etc from CRM will be available in BU1 as Synchronised Data extension. However Child BU 1-1 will not be able to access the synchronised data using "ENT." prefix in sql statement via automation activity
The older approach was run an automation in BU1 to populate Shared Data extension and then use them in child BU. This approach has some limitation:
The design becomes unnecessary complex if no transformation of data is needed.
Data is not realtime. It has 15 mins (CRM data synchronisation ) + additional time to next automation run of delay
Additional Data extension been used and to be maintained
Much better and cleaner solution is , enabling sharing of Synchronised DE
login into marketing cloud and navigate to connected Parent BU (BU 1)
2. Click on Audience Builder - Contact Builder
3. Click on "Synchronized" tab and click on the configured CRM Connection tile.
Click on the "Sharing" tab
4. In "Specific BU" section, select the child BU who need access to parent's synchronised data extension
and save.
Now if you execute sql like below in automation sql activity , it will not fail and will get all contact's name from parent BU
Select name in ENT.Contact