At Level 0 (zero), MS is run for a family of parts. Planning Level 0 means that you enter forecasts for the selected Level 0 part family. A forecast can be a sales plan or another predicted value. Master scheduling (MS) is based on the forecast you enter and the actual backlog of orders. From this information, it creates a master schedule, a manufacturing plan. The calculation also suggests new orders and actions for existing orders.
In addition, MS results in a gross demand, which forms the basis of material requirement planning (MRP). When the calculation is complete, you can study the plan for the Level 0 part. The results are grouped by period. A Level 0 part is a blow-through part and cannot be manufactured; the forecast is simply transferred to Level 1.