How Product Inspectors Use Quality Control Checklists

QC inspectors are your eyes and ears when it comes to checking your product for quality defects and conducting on-site tests. Take the guesswork out of product inspections and learn how to create a QC checklist with all the information your inspector needs to make a decision just like you would!

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Put yourself in the shoes of a product inspector for a second. Erase from your mind all the information you know about your product, your supplier and your customers. Now try to inspect your product for quality issues without that information.

It would be quite difficult, right?

When an importer omits a key detail for inspection, they often receive an incomplete or inaccurate inspection report as a result. In turn, they might end up approving a shipment with a serious quality issue that puts their business and customers at risk.  

A quality control checklist takes the guesswork out of the inspection process (related: 5 Essentials of a QC Checklist [eBook]). Providing your product inspectors a quality control checklist before inspection helps them prepare and clarify any uncertain points ahead of time.

Tailoring your checklist to your specific requirements almost always leads to more accurate inspection reporting. Let’s help you create the best checklist for your products by outlining how your inspectors will use it in the field.

5 inspection steps where quality control checklists are vital

Most product inspections follow a process with several specific steps. When an inspection goes wrong, it’s most often because steps weren’t clear, or inspectors otherwise didn’t follow them according to the buyer’s instructions.

How you’ve designed inspection will impact the time (and cost) needed and accuracy of results. This is true whether you’re conducting inspection yourself or hiring a professional third party.

That’s why an inspection checklist must be detailed enough to include all your requirements yet concise enough to be easy to follow (related: Quality Control Inspection Checklists and How to Use Them).

The following steps are common among most QC inspections and are very difficult without the aid of an effective checklist to reference:

1. Pulling random samples for inspection

Most importers know the importance of pulling random samples during QC inspection using a statistically-significant acceptance sampling method. Without pulling samples randomly, you risk getting a report that doesn’t fairly represent the quality of the entire shipment.

Factory staff can actually hinder inspection accuracy if permitted to choose which units will be checked. Some may “cherry pick” samples or direct inspectors to check units they know will meet requirements from a specific area of the warehouse .

But many importers don’t know that their QC team also references a QC checklist to confirm how large of a random sample they need to pull.

Without knowing what sample size to check, a couple problems can occur:

• Inspectors may check too many units, which will lengthen the time needed to inspect and may raise your costs if your inspector is billing you based on time; or
• Inspectors may check too few units, which limits transparency and raises the likelihood that defects and other product issues will go unnoticed

Any effective inspection checklist must include a point about what sample size to inspect, often based on the industry AQL standard.

Let’s say you’re manufacturing 1,200 wooden cabinets in Foshan, China. And you’ve hired a product inspector to check a “GII” sample size, or 80 units.

Your inspector will most likely refer to your quality control checklist to learn the sample size required. If the sample isn’t stated, they might mistakenly pull a “GI” sample instead, or 32 units. And you’d be overpaying for an inspection with a much smaller scope than you needed.

2. Checking the product against specifications

You might provide your QC team with CAD drawings, an approved sample and other reference materials to clarify product specifications. Your QC checklist should not only direct your inspector’s attention to these, but also list any other specifications they should check during inspection.

A QC checklist typically covers product specifications such as:

• Item weight and dimensions
• Material and construction
• Item color
• Item marking and labeling, and
• General appearance

Professional inspectors look to the quality control checklist for a list of all the product specifications they must check and report on. There’s no guarantee that your inspectors will check information not included on your inspection checklist (related: Why Importers Need a Quality Control Checklist).

For example, if you don’t specify what information should appear on a clothing label, your inspector won’t know what information to verify on site. This can pose serious problems, especially when you’re compelled to meet product labeling regulations.

3. Verifying packaging requirements

Obvious problems with packaging are normally easy to spot. But some of the more specific details are easy to miss during inspection and reporting if you don’t include them in your quality manual.

Your inspector will typically reference your checklist for the exact type of packaging, markings or labeling, artwork and other requirements they must confirm at the factory.

What can go wrong when packaging isn’t reported correctly?

A nonconformity like transparent tape, rather than opaque tape, on a shipping carton may not cause issues for you. But maybe your inspector doesn’t report that the same carton is single-ply when it should be double-ply to carry the weight of your product.

The finished goods you receive could be damaged to the point of being unsellable as a result. Including all packaging requirements in your QC checklist will help ensure your products are adequately protected during shipping and handling (related: Packaging Inspection Guideline [eBook]).

4. Classifying and reporting quality defects

Most products are prone to a set of quality defects unique to their product type. For example, warping is a defect known to affect wooden products. And flash is a defect known to affect injection-molded products.

But without clarification in your QC checklist, your inspector is likely to misreport—or omit from their report entirely—any product defects found.

QC professionals typically classify defects as “critical”, “major” or “minor” in order of severity. And inspection checklists often have a section for defects and how to classify them, which the inspector uses to determine defect severity.

For example, the following excerpt from a QC checklist for furniture classifies an exposed nail as a critical defect. Like other critical defects, an exposed nail could cause serious harm to consumers if not addressed before shipment. So the order will generally fail inspection if the inspector finds one or more in the sample.

But you often need to state a clear tolerance for what’s acceptable for less serious defects, like untrimmed threads on an upholstered chair. Is an untrimmed thread of one centimeter acceptable? How many are acceptable? What about untrimmed threads of two centimeters?

Misreporting or underreporting defects can have serious consequences. The best way to ensure your inspector reports defects appropriately is to:

• Brainstorm an exhaustive list of all known quality defects and
• Classify each defect in your checklist according to your customers’ expectations

Remember that customer feedback plays a key role in effective checklist development (related: 4 People to Consult When Creating a Quality Manual for Your Product).

5. Conducting on-site testing

On-site product testing is an essential part of QC inspection for a wide variety of products. Inspectors conduct product tests to identify any issues that might affect your products’ safety, function or performance.

Product inspectors rely on inspection checklists to provide testing criteria and procedures, testing sample sizes and more. Inspectors might perform testing incorrectly or misreport the result if they’re following an incomplete QC checklist.

Let’s say you’re manufacturing electric blenders—a product with many parts that need to work together:

• The lid must fit correctly onto the container
• The container must fit correctly onto the blade assembly; and
• The blade assembly must fit correctly onto the base unit

A fitting test and function testing are generally needed here to verify that all moving parts work correctly together.

The inspector will reference your QC checklist for this test and its steps. And they likely won’t perform any product tests which are left out of the checklist.

Specify who will provide equipment for product tests

Importers often mistakenly forget to address the testing equipment needed for inspection in their QC checklist (related: 3 Mistakes Importers Make with Quality Control Checklists).

Some importers assume their supplier and QC team will work out the testing equipment if they clarify what product tests they need. This often results in not having the necessary equipment available for testing on the inspection date.

Outside inspectors often bring a few essential tools to product inspections to the factory, like calipers, a tape measure and a barcode scanner, among others. These tools are portable and applicable for most product inspections.

But it’s not typically reasonable for an inspector to supply something as large as a metal detector or lightbox for on-site testing at a factory. The cost of purchasing and the burden of transporting such equipment make it impractical for inspectors to provide them.

An effective QC checklist will specify not only what’s needed for product tests, but also who should provide it. The checklist helps inspectors adequately prepare for what they need to bring to a factory.

And because everything needed for testing is outlined in the checklist, inspectors can call ahead to the factory to confirm the equipment is available.

How to include equipment requirements in your inspection checklist

Below is an excerpt of how you might specify equipment requirements in your QC checklist:

Sometimes it helps to clarify other requirements for on-site testing in this section as well. A “rigid flat surface” is not technically a piece of equipment, but it’s essential to carry out load testing for furniture.

There might similarly be complementary devices or products you need to test your product with. If you’re manufacturing iPhone cases, you’ll want to ensure the proper iPhone model is available on-site to test the fit and functionality of the case.

You might also prefer to provide some inspection equipment yourself. This might include go/no-go gauges, defect tolerance boards or other equipment specific to your product type. You could also add a section to your checklist called “Equipment provided by buyer” for this purpose.

Conclusion

If you were at your supplier’s factory personally inspecting your order, you would want to check certain aspects of your product. And while you might not be available to inspect every order, you can still advise others on how to review your product based on your same standard.

By remaining mindful of how product inspectors use inspection checklists, you can help inspectors help you. With the aid of a QC checklist, your inspectors are more likely to be fully aware of your quality requirements.

When QC staff have a detailed checklist on hand you can sleep more soundly knowing that you’ve provided all the information necessary to conduct a thorough inspection.

Editor’s note: This post was originally published in January 2017 and has been updated for freshness, accuracy, and comprehensiveness.

How has a clear checklist for your product improved your QC experience? Let us know in the comments below!