If more than one requisition line item is associated with the agreement line item, you must use the Requisition Line Items tab to change quantities.
The software does not allow you to update the agreement line item quantity on the Line Items screen, because the quantities that are finally purchased for requisition line items must be tracked to determine if a requisition has been purchased completely.
Select a line item and click Manage in the Other Details cell.
Select Requisition Line Items.
If needed, update the quantities.