Co- and by- products are important products in process manufacturing, they have specific requirements on batch attributes and must be possible to be created in the context of a change order where a new formula or recipe is specified. Currently, co-and by- products must be created outside of the order, because it is not possible to create an engineering product category with the option co- or by- product.

I may be wrong, but it seems to me, all it takes it adding the two options to the lookup.