How do we update cost after ship confirm

We manufacture items with ACTUAL cost and we often don't have costs collected until at least a week after the product leaves our facility.  We want to ensure we have accurate costs for the work order but we're completing and then payroll is producing hours and quantities (a week after). 

How do we ensure that we can complete the sales order process of ship confirm and invoicing and make sure costs are associated with the item relieved from inventory?