In our company we have products that can be manufactured by ourselves or bought to suppliers. The decision between manufacturing or buying a particular product can be made according to:

• Quantities available. If a quick order is confirmed and supplier product delivery not done yet, manufacturing can be done.
• When work load is too high and/or supplier cost lower the product can be bought

Two ways seems feasible to handle this but not completely satisfying:

• Creating 1 bom with bought product and 1 bom with manufactured product selected with a property ("buy" or "manufacture"). The problem is that properties are selected on the sales order only. And this decision has to be made by the manufacturing team only.
• Using both "buy" and "manufacture" routes. But how can the decision been made?

How would you handle this (common I would say) case?