What is the difference between a pre-production sample and a production sample in test records?

Main answer · Wecent Editorial Team

Short answer: A pre-production sample is built before mass production to confirm the design, tooling and process, and may still have hand-made parts or trial settings. A production sample is taken from actual mass production, using the final tooling, parts and process. Test reports should say which one was tested, because only the production sample shows what you will really receive.

Pre-production sample

This is made after the design is nearly final, to prove that the product can be made. It might use early tooling, parts from trial lots or some hand assembly. It is used for design checks, first approval and early testing.

Production sample

This is picked from a normal production run, using the final tooling, the approved parts and the usual line and operators. It shows the real quality and consistency.

Why the difference matters

• Representation. Test results only apply to units like the tested one. A pre-production unit may differ from the final product.
• Certification. Labs and certification bodies need samples that match the production specification. Check what the scheme requires.
• Disputes. If there is a quality dispute, the production sample is the reference.
• Risks. A product that passes as a pre-production sample can fail when production begins, if the process or parts change.

What to write in the records

• The sample type: pre-production or production.
• The date, batch and quantity.
• The design revision and the bill of materials version.
• The tooling status: trial or final.
• Where and by whom the sample was taken.
• Photos and the label on the sample.

What to test at each stage

1. Pre-production: function, safety design review, early compatibility and heat tests, fit and finish.
2. Production: the main performance and quality checks again, plus the safety and compliance tests required for approval, and comparison to the approved pre-production sample.

Keep the golden sample

When a pre-production sample is approved, mark it as the reference, and keep it. Later production samples should be compared to it, and to the specification.

Common mistakes

Using a hand-made sample to get a certificate, and then shipping a different product. Not recording the revision. Mixing reports from different stages in one file.

Quick summary

Label every report with the sample type and revision. Treat the production sample as the real proof.

Where this answer says to confirm with Wecent, the detail is not published on the product page and has to come from the datasheet or the factory. General facts come from the regulators, standards bodies or device makers named in the text.