Customer-supplied material (free issue), and co- and by-products
Material a customer sends in to be made into their parts is held as theirs, at no cost, and used only on their work orders. Anything else a build makes (a second part, or saleable scrap) can be recorded into stock, with its value taken off the part's cost.
Where it is
- Manufacturing → Customer material
- Manufacturing → Orders — Use the customer's own material; record co- and by-products
Receiving a customer's material
Manufacturing → Customer material → Receive customer material. Pick the customer, then the material it is (your own product for it, e.g. 3 mm plate), and how much came in.
The first time, the customer gets their own product for it: the material's name with theirs (e.g. "3 mm plate (Acme's)"), a SKU ending in their name, the same material details, and no cost. Each delivery goes into stock against it. The page lists what each customer has in stock.
Using it on their work order
On a work order for that customer, each material line has Use the customer's own. Enter how much. Their material gets a line of its own on the order and is issued straight away at no cost, and your own material's line needs that much less. Their material can only be used on their orders, and only as much as they have in stock.
Co- and by-products
On a draft BOM revision, Co- and by-products lists what each build also makes: a second part off the same sheet, or scrap that's sold by weight.
On a work order, Co- and by-products → Record one (the BOM's ones are offered first) puts it into stock at its product cost and takes that value off the order's material cost, so the main part carries only the rest. Record them before the order's final output.