When using Production, BOM product quantity is immediately updated so that there is producted quantity on hand. It can't be this way. Items needed in BOM have to be reserved at the beginning of production, while the production process itself can last for days or weeks.
You could say this can be done in business-driven way: Sales person makes a sales order, quantity gets reserved from the stock (?) and then you begin to produce the needed amount. But it's just not how we do it.
Actually the function you really need is manufacturing function. The Production function in Compiere is not designed to accommodate this function. It can only act as a "boxing procedure". So I think you need an extension to do that
Thanks for your reply!
Yes, I've read about Compiere MFG & SCM. The conclusion in our case was that it's not worth installing it: a big, complicated extension, covering a number of the same tasks as Compiere itself, duplicated.
Compiere in itself is already monolithic enough, complicated and in many ways hard to understand, plus hard and time-consuming to set up in production stage. We circumvented the problem by simply adding a new "virtual" locator in the warehouse for the finished products (This could be a whole new warehouse too, because there are some special options where that could be handy, for example replenishment from one WH to other). When the production is complete, the products are moved to that locator, where sales personnel can see them available.