How to qualify a packaging supplier

Most packaging supplier problems we have seen did not start on the production line. They started at qualification, when a supplier was approved on a nice sample, a competitive quote and a certificate on the wall.

Qualification is not a meeting or a form. It is the evidence that a supplier can make the part you specified, with production tooling, at the rate you need, consistently, and that they will tell you before they change anything. Below are the five steps we use to build that evidence, with the research and standards behind each one.

1. Decide how deep to qualify

How it shows up. Teams either qualify every supplier the same way, which overloads the team, or they apply a light process to everything, which leaves critical parts exposed. A stock carton and a custom printed primary container do not deserve the same effort.

What the research says. Peter Kraljic's 1983 Harvard Business Review article introduced a portfolio model that classifies purchases by profit impact and supply risk into four groups: non-critical, leverage, bottleneck and strategic items.^[1] Strategic items, with high impact and high supply risk, deserve the most attention from purchasing.^[2] Critics note that two axes simplify real purchasing decisions and leave out factors such as quality and innovation, so we use the matrix to set the depth of qualification, not to make the final decision.^[3]

In practice. Place each packaging component in one of the four groups before you contact suppliers. Custom, printed, regulated or single-source components get the full process below. Standard, widely available items can rely on certificates and incoming inspection.

2. Write the requirements before the request for quote

How it shows up. The request for quote goes out with a drawing and a volume, and the cheapest compliant-looking answer wins. Requirements on tolerances, cleanliness, documentation, lead time and change control are added later, when the supplier has less reason to accept them.

What the research says. Gary Dickson's 1966 survey of purchasing managers ranked 23 supplier selection criteria. Quality came first and delivery second, followed by performance history and warranties and claims policies.^[4] Dickson also found that price was not a consistently important factor in the selection process.^[4] Weber, Current and Benton later reviewed 74 articles published after Dickson's study and used his 23 criteria as the benchmark for comparing them.^[5] A review of multi-criteria methods in the European Journal of Operational Research concluded that evaluating suppliers against several criteria works better than the traditional cost-based approach.^[6]

In practice. Agree the weighted criteria (for example quality, delivery, technical capability, capacity, cost and risk) with engineering, quality and purchasing before the request for quote goes out, and send them with it.

3. Audit the system, and read the certificate scope

How it shows up. A supplier shows a certificate, and the box is ticked. Nobody checks whether the certified site is the site that will make your part, or whether the certified scope covers your process.

What the standards say. For packaging that touches food, BRCGS Packaging Materials was the first packaging standard recognised by the Global Food Safety Initiative (GFSI).^[7] Issue 7, published on 28 October 2024, replaced Issue 6.^[8] It also clarifies supplier monitoring and traceability, including annual trace tests that must now be completed within four hours.^[9] For primary packaging of medicines, ISO 15378 adds good manufacturing practice (GMP) requirements to ISO 9001 and applies to the design, manufacture and supply of those materials.^[10]

In practice. Check the certificate's site address, scope and expiry date. Then audit the things a certificate cannot show you: how the supplier controls artwork and plates, segregates similar products, handles rejected material and traces a batch back to its raw materials.

4. Prove the process, not the sample

How it shows up. The first samples are perfect. They were made slowly, on prototype tooling, by the supplier's best operator. At volume, dimensions drift, print registration moves and seal strength varies.

What the standards say. The automotive industry's Production Part Approval Process (PPAP) exists for exactly this. Its purpose is to show that the manufacturing process has the potential to consistently produce parts that meet all requirements during an actual production run at the quoted production rate.^[11] PPAP is now used well beyond automotive.^[12] In the AIAG PPAP manual, an initial process study with a capability index below 1.33 does not meet the acceptance criteria and has to be reviewed with the customer.^[13] An earlier edition of the manual described indexes above 1.67 as probably meeting customer requirements, and values between 1.33 and 1.67 as acceptable for starting production only with additional attention to the characteristic.^[14] A common shortcut that weakens these studies is running them under controlled trial conditions instead of at the quoted production rate.^[12]

In practice. Ask for samples from a production run, made with production tooling, at rate. Agree which characteristics are critical, and ask for capability data on those. Your own customer or industry may set different thresholds; theirs decide.

5. Agree on change notification, then keep qualifying

How it shows up. The supplier changes a resin grade, an ink, a sub-supplier or a production line, and the first sign is a field complaint. Qualification was a one-time event, and nobody was watching afterwards.

What the regulations say. The FDA's purchasing controls for medical devices have long expected purchasing documents to include, where possible, an agreement that suppliers notify the manufacturer of changes, so the manufacturer can decide whether a change affects product quality. FDA training material adds that the best practice is notification before the change is implemented.^[15] Failure to evaluate suppliers adequately and failure to set adequate requirements for purchased products are among the most recurring findings in FDA warning letters; the FDA has since adopted ISO 13485 as its quality system basis for devices, where clause 7.4 now covers purchasing.^[16]

In practice. Put a change notification clause in the quality agreement for every packaging supplier, not only regulated ones, and list what counts as a change: materials, sub-suppliers, site, equipment, process and testing. Then review supplier performance on a regular cycle, and requalify after any significant change.

A one-page summary

• Segment first. Qualification depth follows supply risk and impact.
• Requirements before quotes. Weighted criteria agreed across functions.
• Certificates are a start. Check site, scope and expiry, then audit what matters to your part.
• Production run at rate. Capability data on critical characteristics, not hand-made samples.
• No surprises. A written change notification agreement and regular reviews.

Supplier risks belong in your project risk register too. Our free Packaging Project Risk Register includes supplier tooling, minimum order quantity and change control risks, ready to adapt.