Duplicate Connections to Business Analytics Servers
You can define duplicate Business Analytics Server connections with different scopes, such as defining one connection for a SharePoint farm and a duplicate connection for a specific site collection in that farm. This can be useful, for example, if you need to configure a different authentication mechanism for a specific site collection.
When duplicate connections are defined, the site-collection-specific connection overrides the farm-level connection for that specific site collection. All other site collections inherit the farm-level connection.