The core principle is "leave a traceable record at every step," not wait until an audit comes to organize records afterward. In practice, there are several common problem areas: first, inconsistency between the quotation and the actual PI conditions issued, with both parties keeping different versions, making it unclear if disputes arise; second, the same transaction is shipped in batches, but commercial invoices and packing lists don't keep up, resulting in documentation mismatches during export clearance; third, when responding to compliance requirements like EU CBAM, it becomes difficult to find the original supporting documents at that time. The solution approach is to manage every document from inquiry, quotation, PO, PI to shipment in one centralized location, with each submission automatically saving a version record. When comparing version differences between buyer and seller, you can directly pull them up. For shipments, one PI can correspond to multiple batch shipment records, commercial invoices are adjusted for exchange rates, and packing lists support consolidation—all designed in advance so that shipment operations don't require last-minute scrambling.