The process can represent a huge headache for corporations because 1) huge numbers of parts and raw materials go into products and 2) every supplier, from the very large to the very small, has things that it has difficulty accounting for.
只是這部分多半受制於人，一方面是原料及零組件品項極為繁雜，一方面供應商規模從極大到極小各有「難搞」之處，令廠商一個頭兩個大。