Which materials result in a negative quantity in a bill of materials or recipe?

A negative quantity in a bill of materials or recipe typically indicates the removal or deduction of materials during the production process. Waste products are generated when raw materials or components are transformed into finished goods, and during this transformation, some materials are often discarded or lost in the process. These waste products are accounted for as negative quantities to reflect that they do not contribute to the final output of the finished product.

In contrast, raw materials, primary materials, and finished products are integral to the creation and assembly process. Raw materials and primary materials represent the inputs being processed, while finished products indicate the final output of the production cycle. Unlike waste products, these categories do not result in negative quantities because they are either being consumed in the process or are the result of the production run. Thus, in the context of a bill of materials or recipe, waste products specifically account for losses that lead to negative quantities.