This is a fairly odd statement given that BOMs are managed in manufacturing systems and for accounting and engineering purposes in multiple different ways. This can be for anything to do with sales data for a client or for guys on the factory floor or for the accountants. There are sales BOMs, manufacturing BOMs procurement BOMs and nested BOMs etc all for different parts of the business process...you would have BOMs within the organisation that were probably nearly 70% etc or those that were 0%!