On what is the master schedule used by an MRP system based?

1. MRP has to decide what will be manufactured over the coming weeks or months. 2. It cannot know that from orders alone, because materials must be ordered before demand arrives. 3. The master schedule is therefore based on forecasts of demand for the company's products. 4. The schedule then states exactly what will be manufactured and when the work will take place. 5. The computer compares those production needs with the materials already on hand and orders the difference. 6. Because the whole chain starts from a forecast, a poor forecast propagates into wrong materials arriving, which is the standing weakness of the method. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 10 "Achieving World-Class Operations Management", section Computerized Resource Planning_