Think of a company like Rajesh & Co. Pvt. Ltd. manufacturing ceiling fans. Before the year begins, every department — Sales, Production, Purchase, HR — needs its own spending and output plan. That's exactly what Functional Budgets are: individual budgets prepared for each function or department of an organisation. Together, they roll up into the Master Budget.
The preparation always starts with the Principal Budget Factor (also called the Limiting Factor) — the one resource that constrains everything else. Usually it's sales demand, but it can be machine hours, raw material availability, or skilled labour. You identify this first, build the Sales Budget around it, and then cascade downward. The sequence matters: Sales Budget → Production Budget → Materials Purchase Budget → Labour Budget → Factory Overhead Budget. Supporting budgets like the Selling & Distribution Budget, Administration Budget, and Cash Budget run in parallel. Each functional budget feeds numbers into the next, so an error in the Sales Budget ripples through all downstream budgets — examiners love testing this chain.
The Production Budget is the pivot point. It converts the sales target into units to manufacture, adjusting for opening and closing finished goods stock: Production Units = Budgeted Sales + Closing Stock of FG − Opening Stock of FG. From production units, you derive the Materials Budget (units of material needed) and then the Purchase Budget (add closing RM stock, deduct opening RM stock). The Labour Budget converts production units into hours and then into ₹ cost using standard hours per unit and wage rates. The Cash Budget is the final integrator — it picks up cash inflows from the Sales Budget and outflows from all other functional budgets, flagging months where the company might run short. This is asked frequently as a 5–8 mark question in the CA Inter exam, either as a standalone production/purchase budget or as a combined multi-budget problem.