Recently I was asked what the “20% of efforts that give 80% of results” are when it comes to quality control in China. Interesting question.
Well, first is to find the right supplier. That’s probably the most important thing you can do, if you need to manufacture products in China. It is necessary. But it is not sufficient.
Aside from supplier selection, there are three steps that I feel are indispensable. Most experienced buyers never skip these steps. Here is how I’d represent them.
1. Product specification sheet
Before you confirm an order to a Chinese supplier, you need to explain what you want. In other words, define your expectations before you inspect production… and might complain to the supplier.
A good specification sheet includes:
- How the product needs to be checked, and what is expected
- How the product should be labelled and packed
- What the tolerances are on measurements
- What the potential defects are and how to classify them
Note that you should be aware of your country’s regulatory standards, and you should include related considerations in the specification sheet.
If you are not sure how to document all this, you can use our spec sheet template.
(If you are involved in the design and development of your product and you have a lot more information to share with your supplier, you might want to use our design file template.)
If you want to go further, here are some extra tips.
A ‘good practice‘ is to highlight what product characteristics are “critical to quality” (CTQ). For example, if you buy metal parts that will need to be assembled, certain dimensions will be CTQ (since they might make assembly impossible). If you buy promotional items, the position and the color of the logo are CTQ. If you buy funeral urns, the absence of any hole or gap is CTQ. You get the logic.
(Note: “critical to quality” doesn’t necessarily mean it triggers “critical defects”. But it has to be checked more carefully.)
A ‘best practice‘ is to also define how the processes that impact CTQ characteristics are to be controlled. For that, you need to understand how production is organized and what processes are involved, and you need to discuss with engineers in the factory.
Another ‘good practice‘ is to sign an OEM agreement with the supplier. The specification sheet should be an appendix to that contract. This way, if the supplier doesn’t respect your quality standard. you can put pressure on them. We are not lawyers but the China Law Blog put out good articles on this topic.
A few notes about samples…
What about the approval of a perfect sample?
Many buyers work solely on the basis of a sample. Their purchase orders and their contracts mention “production should conform to approved sample”. This is quite common in the garment business, for example, where a sample, a size chart, and a packing manual play the role of specifications.
To be sure, samples do play a role. They are superior to a written specification sheet in several respects:
- They indicate the touch & feel that is expected better than any written description.
- They show what color is expected more precisely than a Pantone code. Note that a best practice is to have boundary samples (“try to be very close to sample A; it can be a bit darker but no darker that sample B, and a bit lighter but no lighter than sample C”).
- They can be used to run some tests — for example a fitting test, if the part to be produced has to be assembled with another part later on.
What other physical elements might be needed?
Inspectors often have to use a special testing device. Sometimes that device is standard (for example a laser measurement tester from a certain brand); in some cases, the buyer and the manufacturer have to custom-develop a testing apparatus and agree to use it for validating production conformity.
These testing devices, just like approved samples, should be mentioned in the product specification sheet.
2. Pre-production and production sample review (in an office)
There is a two-way relationship here. The spec sheet makes sample reviews more structured, and sample reviews will help you make the spec sheet better.
As part of the development before production starts, the supplier will send you samples. You should use the specification sheet as a checklist. It will structure your feedback to the supplier, and it will help you refine the specification sheet (for example you will think of new potential defects).
Once production is under way, you should also request samples from the supplier. (This might not be realistic if you buy large items.) Hopefully, these samples will be fully packed. Again, use the specification sheet as a checklist. It is not too late to make changes to the spec sheet and send a new version to the supplier.
Once you have used the spec sheet successfully as a checklist, the inspector you send to the factory will be in a position to do the same. And, hopefully, the supplier also uses it as a checklist in their internal inspections.
3. Product inspection (in the factory)
If you let a Chinese supplier ship the goods to you and you discover they are not acceptable after delivery, it is way too late to do anything. You will probably have paid the order in full at the point, and there is virtually no way of sending the goods back to China for rework.
That’s why serious importers inspect the products during production and/or after production (a few days before shipment). You can do it yourself or hire a quality assurance agency.
When to conduct the inspection?
During production — allows you to catch issues, if any, early in the process. This way, you can request corrective actions and go back to check a few days later. It is much easier to make “adjustments” before all the goods are completed and packed.
After production — allows you to check the quantity, the packing & labelling, and the average quality (since you can really pick samples at random and see what average quality is like). A passed inspection, at this point, means the supplier can ship out.
If you prepared a complete specification sheet, the inspector will know how to categorize most of the defects, and will know if the batch should be accepted or rejected (based on the AQL limits you have set in the spec sheet).
In other words, if you have done a good job with the spec sheet, there is little room for discussions. In case serious issues are found, the supplier won’t have many excuses and you won’t spend hours arguing with them.
How to make sure the supplier re-works or reproduces at their cost, in case serious issues are detected? You need significant leverage in the relationship. There are mainly 2 ways of achieving that goal:
- You haven’t paid a portion of the order yet;
- The supplier signed and chopped a legally enforceable contract that refers to the spec sheet.
Another big advantage of a detailed spec sheet is that it makes the inspection process less subjective and more accurate. The inspector will know what to look at in priority, and will be less likely to listen to the factory’s arguments.
(Note that some samples can be picked by the inspector and sent to a laboratory for testing. If you trust the supplier 100% when it comes to your country’s regulatory standards, you are taking risks — especially in categories such as electrical products, toys, cosmetics, etc.)
If you want to go further in reducing your risks, I suggest you read What Needs To Be Done Before Production Starts.