We have  scenario where most of our products are purchased on a ‘Make to Order’ basis. 

We therefore raise a sales order (which creates the waiting availability sales delivery) and then run the scheduler to create the purchase order (which in turn creates the incoming shipment).

We would then like to update the expected delivery date on the Purchase order or the scheduled date on incoming shipment and for this to be updated on either the sales order or on the waiting sales delivery.  Is this possible?