Where does the traditional budgeting begin?

The traditional budgeting starts with the production budget.

financial budgeting is a workflow in which enterprises scientifically and reasonably plan, predict and measure future operating results, cash flow changes and financial status according to their own business objectives, and systematically reflect relevant data in the form of financial accounting reports.

the production budget is prepared according to the sales budget, and the resources needed to meet the sales volume during the budget period and the ending inventory are planned.