A distinct shortcoming in the composite items feature of Inventory is that whilst it provides a degree of bill of material functionality it fails to handle the situation where you are selling composite items as finished products on customer orders ie. you don't carry any raw materials or finished products, everything is put together as and when you receive customer orders.

The Composite Items feature doesn't support "just in time" inventory in that you can't create the bundles to be sold via a Sales Order or Invoice while you don't have any stock. If Inventory allowed you to create such bundles and then identified the raw materials that need to be placed on backorder with suppliers then our issue would be largely resolved. There is a bit more to this but certainly overcoming this would enable the Inventory application to be adaptable to a much wider market.