Factory audit checklist: one day on the floor

What an audit is actually for

A site visit is not a formality and it is not a box-ticking exercise. Its purpose is to answer the one question documentation cannot: is the process real, or is it performed for visitors? Everything you see in a day should be read against that question. [Deming, 1986] argued that quality cannot be inspected into a product but has to be built into the process — an audit is the closest you get to watching that happen.

The walkthrough, in production order

1. Material store. Materials should be identifiable — labelled, dated, separated by batch — not loose sacks. Ask to be shown the incoming inspection location and its records.
2. Incoming inspection bench. If it does not exist, nothing downstream can be trusted. Look for simple instruments actually in use: durometers, calipers, a scale.
3. Assembly line. Count stations and operators; note whether work instructions are posted and readable. Torquing, potting and soldering are where failures originate in this category, so look specifically at those stations.
4. Rejected parts. The most informative minute of the day. There should be a physically separate, clearly marked location for rejects, with units in it. Empty-yet-existing is plausible; absent altogether is not.
5. Testing area. Function rigs should be running on units that are in the queue, not clean and idle. Ask to see a unit being tested and the record it generates.
6. Packing and documentation. Look at a finished carton being packed and at the documents that will accompany it. Missing documents discovered here cost a day; discovered at customs they cost a shipment.

Reading what you see

Three questions to ask a person, not a document

Documents are written once. A conversation is harder to script, so these are worth asking an operator or a line supervisor rather than the sales contact.

• "What do you do when a unit fails here?" The answer should name a bin, a record, and a person — not a shrug.
• "How do you know this batch is the material you ordered?" A plausible answer names a check performed today.
• "What did you reject most of last month?" A real process has a known failure mode and someone trying to reduce it.

If you cannot visit, commission a third party. Any inspector you appoint may attend at the factory address — including for our own range, where there is no coordination fee and no restriction on who you use. Pair the visit with the AQL inspection planning you will apply at shipment, so what you audit matches what you later accept or reject.

Where our own line sits

Production runs through our manufacturing partner in Dongguan, Guangdong, operating since 2014 with tooling, assembly and quality control under one roof and no subcontracting on core components. Capacity is published at 500,000 units a month across 80+ staff including 20+ dedicated QC. Those are numbers you can check against the line: count the stations, then decide whether they are consistent with the order you intend to place. The technology and compliance page sets out the four inspection stages, and the supplier vetting checklist is the written counterpart to this visit.

References

1. Deming, W. E. (1986). Out of the Crisis. Cambridge, MA: MIT Center for Advanced Engineering Study.
2. Juran, J. M. & Godfrey, A. B. (1999). Juran's Quality Handbook, 5th ed. New York: McGraw-Hill.
3. Montgomery, D. C. (2020). Introduction to Statistical Quality Control, 8th ed. Hoboken, NJ: Wiley.