1. The budgets can be stored inside the data warehouse. This is typicall in another fact table and usually at another grain than the fact table with the "actuals". For example: budgets are at quarterly level, facts at daily level. This means you have to do some aggregation on the actuals before you can link them to the budget. Or you can break down the budget to the daily level.

An example of a budget fact table:

The Budgeting Chain[/url]

2. Budgets can come from anywhere. From Excel or maybe from MDS. But they can also come from applications, like SAP BPC for example.