Many things may contribute to updating a BOM. The most obvious is any change to a material or trim, or to the colorways a product is produced in.

Different versions of the BOM may also be required to reflect different product states (concept, development, and production). A BOM becomes complete as it evolves from first concept and initial samples to actual production. Other versions of the BOM can result from a product with multiple versions (the same or different seasons), such as lined or unlined, pockets or no pockets, short sleeves or long sleeves, cuffs or no cuffs, and so on.