A forecast in Cetec is like a temporary order, and can be activated in the config settings. When you create a forecast, it does not affect the shop floor or create any official orders, but it shows what supplies would be needed and when theyd be needed if this order were created. Its a way for the purchasing or material planning (for subassemblies) department to get ahead.

MRP will by default only account for actual orders in the system. However, if you are utilizing forecasts and you want purchasing to also account for potential orders (forecasts), you would want to click that checkbox next to Include Forecasts in Next Allocation Run?