How do you calculate the cost of poor quality from a bad lot of purchased parts?

Which cost lines usually make up the bill?

Which line dominates depends on where the defect was caught: at receiving it is mostly sorting, re-inspection and handling, while once the parts reach production, line stoppage and scrapped or reworked assemblies can quickly outweigh everything else. Administrative time is small per incident and easy to leave out.

The ranking depends on where the defect was caught. A lot rejected at receiving inspection costs little beyond re-inspection, handling and the delay. The same lot found after parts were built into subassemblies carries the value you added to every assembly that now has to be torn down or scrapped. A lot that escaped to your customer adds field returns, warranty work and whatever your own customer charges you. The worksheet below lists the lines in the order they usually appear, with a formula for each and the record that supports it.

Which costs can you charge back to the supplier, and which stay with you?

Under US commercial law, incidental costs such as inspecting, handling and shipping rejected goods, and the extra cost of buying replacements elsewhere, are recoverable from a seller in breach. Consequential losses such as lost production and your customer’s charges are recoverable only in narrower conditions, and supplier terms often limit or exclude them; for a cross-border purchase, check first whether the UN sales convention (CISG) applies instead.

Article 2 of the Uniform Commercial Code, which governs sales of goods in most US states, lists incidental damages as expenses reasonably incurred in inspection, receipt, transportation and care and custody of goods rightfully rejected, commercially reasonable charges in effecting cover, and any other reasonable expense incident to the delay or other breach (UCC § 2-715, Cornell LII). The price difference on replacement parts bought elsewhere is a separate item: a buyer who covers in good faith can recover the cost of cover minus the contract price, plus incidental and consequential damages, less expenses saved (UCC § 2-712). Consequential damages, the same section says, cover losses from requirements the seller had reason to know about at the time of contracting that could not reasonably be prevented by cover or otherwise. That condition is why a line-stoppage claim is much stronger when the purchase order told the supplier the parts feed a production line. Sellers may also limit or exclude consequential damages in their terms unless the limitation is unconscionable (UCC § 2-719), so read the supplier’s quote terms and your own PO terms before you send a number.

US federal contracts show the same pattern in plain clause language. The fixed-price inspection clause lets the Contracting Officer charge the contractor for any additional cost of inspection or test when prior rejection makes reinspection or retest necessary (paragraph (e)(2)), and, if the contractor fails to promptly remove, replace or correct rejected supplies, lets the government have them replaced or corrected and charge the cost to the contractor, or terminate for default (paragraph (h)) (FAR 52.246-2). A commercial supplier quality agreement can borrow that structure, but only what it actually lists is agreed; anything beyond it has to be written in.

If your company and the seller have their places of business in different countries that are both parties to the United Nations Convention on Contracts for the International Sale of Goods, the convention governs the sale unless the contract excludes it, and UCC Article 2 does not. The United States has been a party since 1988 and Viet Nam since 1 January 2017; the United Kingdom is not a party (UNCITRAL, CISG status). Under the CISG, damages equal the loss, including loss of profit, caused by the breach, capped at what the seller foresaw or ought to have foreseen as a possible consequence when the contract was made (Article 74), so the use statement on your PO matters just as much there (CISG text, UNCITRAL).

Use the decision list below to sort your worksheet before the claim goes out. This is general guidance on how buyers structure claims, not legal advice; for a large claim or an international sale, have counsel read the governing terms.

• Usually recoverable: sorting and re-inspection, handling and storage of rejected parts, return freight, premium freight for replacements, and the price difference on cover purchases.
• Recoverable if the contract says so or the supplier knew: line stoppage, rework and scrap of your assemblies, and your administrative hours, especially when a quality agreement sets a fixed charge per incident.
• Usually stays with you unless negotiated: lost margin on missed sales, your customer’s penalties, field recalls, and costs you could have avoided by inspecting at receipt.
• Never in the claim: normal receiving inspection, costs caused by a drawing revision the supplier did not have, and costs from damage after delivery.

How should the cost of poor quality change the next sourcing decision?

Add the unrecovered part of the cost of poor quality to the supplier’s price when you compare sources, spread over the volume bought from that supplier in the same period. A cheaper unit price can lose to a higher-priced one once its failure costs are counted.

Keep a running total per supplier and per part number: the cost of poor quality you absorbed, divided by the quantity received. Put that figure next to unit price, freight and duty in the comparison; the landed cost guide covers the other lines. ISO 10014 gives top management guidance on realizing financial and economic benefits by tracking quality performance metrics and acting on them (ISO 10014:2021), and a per-supplier COPQ line is one of the simplest such metrics a purchasing team can keep.

Look at the pattern as well as the total. Repeated small incidents on the same characteristic point to a process the supplier does not control, and the fix belongs on the drawing or in the inspection plan. A single large incident with a sound 8D may not justify moving the part at all, because a source change carries its own first-article, tooling and qualification cost.

How is a nonconforming lot handled on a Saola order?

Your purchase order sits with one contracting party, Aximora Global Trading Co., Ltd., which trades as Saola Manufacturing, whichever plant made the part. Put your cost-recovery and corrective-action terms on the RFQ so they are agreed in the written quote before production starts.

Machined parts are made by CNC turning and CNC milling at our lead CNC plant, T.K Viet Nam Precision Company Limited in Vietnam. Die castings, sand castings, stampings and all surface finishing are made at partner plants we manage, which are not necessarily in Vietnam; each quote names the production site and the country of origin. Either way, the NCR and any claim come to us, and we take it up with the plant that made the parts.

Because the contracting party is a company in Viet Nam, a purchase by a buyer in another CISG country, the United States included, falls under the convention unless the contract says otherwise. State the governing law, the use statement and the recoverable costs on your PO or RFQ so that the written quote confirms them.

The records your cost claim depends on are part of the documentation described on the quality page: a first-article inspection report for a new part, a dimensional inspection record with every production lot, and material certification on request. If a first-article measurement is out of tolerance, the plant stops and tells you before a sample ships, with the measured value against your print and a proposed fix. ISO 9001 certification is in progress and not yet held, so state in the order any quality-agreement terms you rely on. To quote a part with those terms attached, send the drawing through the quote form.