Product Inspection

Understanding Inspection Methods for Chinese Suppliers

what are the methods of inspection

What are the Methods of Inspection?

Online marketplaces like Amazon and Walmart have provided access to thousands of new resellers looking to make their mark on the retail industry. The backbone of a successful reselling business is partnering with reputable suppliers to source quality products.

For many, the process of finding the right suppliers is difficult when the factories are on the other side of the globe. Language barriers, time zone differences, and cultural nuances make it all but impossible to manage the fulfillment process from sourcing to shipment.

The cost of using a third party inspection company is minimal compared to the potential savings of ensuring that your suppliers are reputable and are performing quality work. In a domestic factory, every step of the process is checked for quality. From initial production to preloading the containers, a third party inspection company can be your eyes and ears in foreign factories.

1. Initial Production Check

An initial production check is the first step in your quality control process. Occurring at the beginning of a production cycle, an inspector checks the materials and processes used in the plant against the master samples and prototypes previously provided.

An initial production check is important for identifying and correcting errors before it is too far into the production cycle. It can also protect you from being undercut with cheaper materials than previously discussed.

Initial production checks also serve as a metric to evaluate your supplier’s ability to handle production volume. While we would all like to believe in the honesty of those we do business with, an underprepared or understaffed factory will only continue to cause problems and cost money down the road. Early intervention when there is a problem is your best line of defense.

2. During Production Inspection

Our inspection services are not limited to finished products. We will happily inspect raw materials and early production processes to ensure that everything is in line from the beginning.

Production inspections are sometimes necessary to avoid rejecting entire batches. It can be necessary to complete routine inspections on raw materials when working with new suppliers or those who have demonstrated questionable quality in the past.

This type of inspection can save a lot of time by identifying key issues early. And time is essentially another way of measuring profitability, so your company is ultimately saving money by saving time.

The timing of a production inspection is important. Just like anyone learning a new skill or, in this case manufacturing a new product, the early samples will be of lower quality. As the manufacturer perfects their skill or process, the quality of work will increase relative to their experience.

Samples taken too early into a new production run will not represent the average quality of the finished product. There are some notable exceptions depending on production times for different products, but most orders should be inspected between 20 – 30% complete.

If you wait too long to conduct a production inspection, likely, the majority of the lot is complete before you have had a chance to identify any flaws. Waiting too long into the production cycle can render the inspection useless and cost the supplier and buyer more money in the long run.

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3. Pre-Shipment Inspection

Pre-shipment and container loading inspections occur on finished products. This type of inspection is too late to identify quality issues with raw materials or production processes. However, it is still invaluable in making sure that quality product is what leaves the port.

Pre-shipment inspections are detailed audits that inspect finished products for quality and description matches for size, color, weight, and functionality. This inspection also checks to ensure that the product inside the cartons matches the labeling on the outside of the cartons.

We check to make sure that all products are labeled in accordance with global trade regulations to prevent delays in export or import. The pre-shipment inspection occurs when the product is approximately 80% complete and loaded onto the container.

4. Production Monitoring

Inspections timed at specific intervals during production are useful to identify potential and existing problems. But what do you do when these spot checks or one-day inspections continue to turn up concerns? While it could be a sign that it is time to find a new factory, more detailed production monitoring can help smooth out the problems.

This type of inspection is also warranted on large-scale projects where there are plenty of opportunities for errors to occur in between traditional production spot checks. The biggest advantage of continuous production monitoring is the real-time feedback as changes are implemented.

There is a possibility that the factory will see this type of monitoring as an attempt at micro-managing their production. These types of negative feelings can create conflict between the factory and the inspector.

The best way to prevent these issues from impacting your business relationship with the factory or the inspector is to be open and upfront about your intentions for using production monitoring. While you may not prevent all conflict, being open about using continuous production monitoring can improve the situation.

Production monitoring can be done for specific intervals of time or on an on-going basis. The costs associated with this type of inspection are significant due to the labor required by the inspector. But compared to hiring a direct employee in another country, production monitoring offers the next best option when you need to be more hands-on at the factory.

5. Container Loading Check

When completed merchandise is ready to ship from the factory to your warehouse in the United States, the manufacturer loads the product onto a sealed container and transports it to the dock to be loaded on a vessel. The container goes through export customs at the dock and must meet legal regulations to export and be accompanied by all appropriate paperwork.

Once released, your container travels by ship until it reaches the port in the United States. It comes off of the ship and passes through import customs on the US side before going into the logistics system of rails and trucks to get it to your location. As you can imagine, the cost of transport is high, and many businesses want to be sure the product they pay for transportation on is sellable when it arrives.

Container loading checks can be an invaluable tool for assuring products’ accuracy and quality as they are loaded and sealed into a container. If you plan to consolidate products from multiple suppliers or you need to be sure that all cartons are in good retail condition, a container loading inspection can be helpful.

An inspector can look at the outer packaging, open a limited number of cartons to verify product matches, evaluate handling procedures, and inspect the container’s condition. An inspector will also verify the proper seal and accompanying paperwork to ensure that your container seamlessly passes through customs.

Selecting Samples for Inspection

Choosing samples for inspection at any stage of the process can be done in a few different ways. Whether you are using a random sampling method or a more calculated process, inspecting products at different stages in production and as the finished product is loaded onto a container can help US-based distributors work more effectively with China-based suppliers.

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Spot Checking Versus AQL Sampling

Product checks can be as detailed as checking the raw materials and finished product against various metrics like size, function, and color. Or, inspections can be more limited purpose like checking the labeling and condition of the outer packaging.

For many retailers and small lot sizes, a few samples picked at random for inspection provide sufficient information to determine if the lot is acceptable or not. Therefore, spot check sampling is the most common and least expensive method of sampling for inspection.

For larger enterprises, large volume shipments, and new partnerships, more calculated sampling selections are often needed. This is where Acceptable Quality Limit or AQL sampling comes in. Using AQL, the sample sizes and selection methods are based on statistics relative to the lot’s size.

AQL sampling provides more reliable data than random sampling. It ensures that an adequate percentage of the finished product is inspected to give a good representation of the entire load. For sellers interested in tracking the data and comparing numbers from different production runs side-by-side, AQL is a more reliable sampling method.


There are many nuances to the world of global trade. In China, a vast manufacturing network can produce nearly any product imaginable for pennies on the dollar compared to factories based in other countries.

On the flip side, there is an entrepreneurial spirit in capitalist countries like the United States that drives the demand for products manufactured at low costs. It seems like it might be the perfect partnership that allows both Chinese manufacturers and American resellers to profit.

Unfortunately, there are many opportunities for failure in a global trade deal simply due to language barriers and differences in cultural and social expectations. Not to mention, it can be costly to travel back and forth between China and the United States to conduct business. A third-party service can facilitate these trade deals by acting as an intermediary.