Question

loading data from ods to cube

SAP analytics and reporting, ODS (Operational Data Store), InfoCube, SAP BI

can u tell me y should we first load data into the ods and then into the cube??
please give examples .... If it is done in specific cases only where the need of the situation demands then please give me examples of such situations.

A first level ODS, you always store future objects, which you know the business might need.
A second level Cube, which have only object that business use currently. This will save time for loading.

Ex: Later on when business need to add an object that does't exist in the Cube and also need historical data. You don't have to run Init Set-up on R/3 side(require R/3 down time) and delete data in the cube then re-init load on BW.

Hope this help