Used for order advice, the forecast theoretical stock is calculated as of the first production day selected. It takes into account the current theoretical stock as well as deliveries and stock removals that will take place before the 1st day of production.
How is forecast theoretical stock calculated?
Theoretical stock on future date D of product P (quantity in US) = Today's theoretical stock of P + Order in progress of P+ Delivery in progress of P - Quantity of P required before period (=Forecast production)