When we issue purchase orders for new stock inventory, there is a delay of up to 3 months (for production, testing, and shipping) before we actually receive the items. During this time we allow our sales people to place orders against the items even though they are not yet received in Sage. The method used to track these sales is to simply attach a paper copy of the orders to the paper copy of the POs, and then when the items are received to modify the orders to use the lot numbers of the received items. This method is flawed because it leaves open the chance that two salespeople could over sell the item, since all they see is the amount outstanding on POs, without taking into account that quantity already reserved for other orders. Further, staff involved with reordering stock can't easily see that the incoming items have already been sold, so the decision as to when to reorder inventory is delayed.

The solution I am planning to implement is to use optional fields on the PO line items to track how much of the item is reserved, and then subtract this value in the reports used by salespeople and purchasers.

Is there a simpler (built in) way to accomplish the same thing without using optional fields?