I need something that would control stock quantity by a shared attrubute, For example we sell auto parts and all parts have multiple years makes and models of fitment when we upload these items they are assaigned there own sku for magento but the real sku that on warehouse uses to moniter quanitity is listed in a attribute. I would like to use this arrtubute to lower quantity when a invoice is made of everything that shares that Common attrubute value. Any advice what be highly appriciated Thnaks.