Notes · Operations, projects and managers
Customer audits versus certificates
I know the ISO and IATF requirements well, but I did not deploy or run those systems myself: quality specialists did. What I know best is something different, and harder: the supplier audits that carmakers run themselves.
Two different questions
A certificate such as ISO 9001 or IATF 16949 answers one question: does this company have a quality system that an independent body has audited? That matters, and it is where most suppliers start.
A customer audit answers another: can this supplier make this part to our requirements, every time, and prove it? The one I know best belongs to a carmaker alliance. It is much more technical and precise than the general standards.
What that precision looked like to me
In automotive I was used to instructions that start from the customer’s 2D or 3D definition of the part, with its tolerances and a clear control method: what to use, and how to measure. A customer audit tests whether a supplier really works that way, and a vague answer does not satisfy a precise question.
Where audits press hardest: shared capacity
The gaps customer audits raise most often are about the capacity available on shared production means. The customer wants the supplier to commit a share of that capacity to its parts, yet it will neither book that capacity nor pay to reserve it.
So the task is to convince the auditor that the capacity is there under normal circumstances, and to explain what happens when something goes wrong. In our case the answer was the group’s other factories: they had similar, matching equipment and could take over part of the workload and balance it when needed.
What I took into a bag factory
On most sewing lines the control method is much less defined: what to use, how to measure. So I now try to define how a requirement is checked before I ask anyone to meet it. The point is made at more length in the note on managing machines and managing people.
What to ask a supplier, whatever the industry
- Which requirement does this check, and who wrote it?
- What do you measure it with, and how often?
- Where is the result recorded, and who reads it?
A supplier who can answer these three questions for one real part tells you more than a wall of certificates.
Questions this note answers
- Is an ISO 9001 certificate enough to qualify a supplier?
- It shows that a quality system exists and has been audited. It does not tell you how a given part is controlled. Ask how each requirement is defined, measured and recorded.
- What do customer audits most often question?
- In my experience, the capacity available on shared production means. The customer asks for a committed share of capacity without booking or paying for it, so the supplier must show the capacity is there and how it would be backed up if something went wrong.
- What is the difference between IATF 16949 and a customer audit?
- IATF 16949 is the automotive quality standard, audited by a certification body. A customer audit is run by the carmaker itself, on its own requirements and its own parts, and is usually more technical and more precise.
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