Warehouses must be assigned to the forecast run header to be used to reserve and issue material.
Click on Assigned Warehouses button, to open the Assigned Warehouses screen.
In the second block Warehouses to Forecast/Reservation Run, enter a sequence number in the Seq field, and select the warehouse from the LOV in the Warehouse field. All warehouses assigned to the login user on Warehouses to Users screen are available for selection. Select the check box of all the warehouses you want to assign, and click Fill In.
The forecast run searches in the assigned warehouses for the required material in the order specified by the sequence.