We are a small company with a complex supply chain, so it is not practical for us to do full audits of our vendors.  We buy our components from reputable suppliers that have their own conflict mineral policies and the resources to enforce them.  We check for a conflict mineral policy when adding new suppliers and do spot checks occasionally.  If we ever become aware that one of our components contained conflict minerals, we would switch to a conflict-free component as soon as practical.  If no direct replacement is available, that would involve a design change (which we would do).