Top-Down Approach

External Sources (ETL) >> Data Warehouse >> Data Mining
                                         >> Data Mart 1
                                         >> Data Mart 2

In the words of Inmon

“Data Warehouse as a central repository for the complete organization and data marts are created from it after the complete data warehouse has been created.”

__

Src: https://www.geeksforgeeks.org/data-warehouse-architecture/