QC Inspections: Why some Points are NOT Checked on All Samples

When it comes to random inspections (usually conducted based on AQL tables), the inspector has to check a certain number of pieces. For example, if there are 5,000 pieces in the whole batch, he/she has to check 200 pieces (in normal severity, level II).

If the inspection was properly prepared, the inspector has certain checkpoints to follow. However, does it mean that these points have to be checked on all samples (in my earlier example, on 200 pieces)?

This is usually not realistic.

Let’s take an extreme example: an inspection of Android phone. Doing a full function check on 1 piece could take an entire man-day. So it is not realistic to check all functions (as per the instruction manual) on all samples, in this case.

Very often there are checkpoints that take more than a few seconds per piece. If the inspector checks all these points on the whole sample size, it can easily get the workload from 1 man-day up to 5 man-days. This is quite common.

To drive my point home, here are a couple of examples:

  • Checking the size of the export carton — it usually makes sense to measure one carton, and to have a quick look at the others (“are they roughly the same size?”).
  • Abusing a product for 5 minutes to see if it breaks or gets deformed easily — do this on 200 samples, and just this one test will take 1,000 minutes, or 17 hours.

So, in my mind, the logic should be as follows:

1. What we can check very fast (in the case of your product: visual defects, fitness test between lid and body…) is checked on the whole sample size.

2. What we can’t check very fast is divided in two categories:

2.a What is very important to the buyer (“critical to quality”), doesn’t take a very long time to check, and/or might vary substantially from one sample to the next due to the production process: can be checked on the whole sample size but it might increase the workload substantially.

2.b Other checkpoints: to be checked on a smaller sample size.

A few more remarks:

  • In the 2.a case, any problem is classified as a defect, just the way a visual defect is counted. It makes sense since all inspection samples were checked for this point (and the statistics from ISO 2859-1 were respected).
  • In the 2.b case, let’s say a point is checked on 5 pieces and one problem is found on 1 of the 5 samples. The inspector can simply consider this problem as critical, which means the checkpoint is failed. And then the buyer (or the quality manager) decides whether it is critical or not.
  • This is a bit crude but that’s the way most inspection firms have been doing for a long time. The alternative would be to inspect all points on all samples, but usually that’s out of the client’s budget.

How a Mobile App can Help Quality Control Inspectors

Over the past 10 years, most buying offices have pushed their inspectors to switch from paperwork to a laptop, and to prepare their reports on Microsoft Excel or Word. It means many details (including photos) can be reported. But it is an inefficient process.

Switching from laptop to an app on a tablet is the next step. We have worked on a nice infographic to explain the benefits it provides. Here it is:


More details at www.syncontrol.com.

Managing your Product’s Life Cycle

Every product has a life cycle. Think of a car: it comes out on the market and attracts attention, then gets more common on the roads, then needs a redesign, and after some time most models’ production gets stopped.

When it comes to most consumer goods bought from China, new designs are often copied very fast — sometimes with the active help from the manufacturer!

That lifecycle is broken down into a number of different stages, as shown in the model below:


I broke down the different phases.

1. Product Lifecycle Part 1

1.1 Design and Introduction

This stage mainly concerns the development of a new product, from the time it was initially conceptualized to the point it is introduced on the market and starts to sell. The company that first had the innovative idea often has a period of monopoly until competitors start to copy and/or improve the product (unless a patent is involved and respected).

1.2 Characteristics

  • Financial drain (this can be seen on the Profit per Unit line on the graph above)
  • No sales profit, all losses
  • Low sales volume
  • High development effort

2. Product Lifecycle Part 2

2.1 Growth and Competitive Turbulence

If the new product is successful (many are not), sales will start to grow and new competitors will enter the market, slowly eroding the market share of the innovative firm.

The first competitors to market the same product might be piggy-backing on the development efforts of the innovator by using the same Chinese factory (and slightly tweaking the design to avoid legal risks)!

How to reduce the risk of having your Chinese supplier sell the same, or a very similar, product to other companies? Here are a few ideas:

  • Source components from Chinese suppliers and put them together in your own country.
  • Alternatively, work with a Western-owned factory in China to do the final assembly. They will be more sensitive to IP rights issues.
  • Work with a large Chinese manufacturer that has a history of developing new products with Western customers, and have them sign the right type of contract (work with a lawyer very familiar with China law — here is one reason why).
  • Develop a strong brand (read about the example of Samsonite here).

2.2 Characteristics

  • Cost of Goods Sold (COGS) reduced due to economies of scale
  • Sales volume increases significantly
  • Increased profitability
  • Staff expansion, bring skill in-house
  • Production planning

3. Product Lifecycle Part 3

3.1 Maturity

At this stage, the product has been standardized, is widely accepted on the market, and its distribution is well established.

3.2 Characteristics

  • COGS are very low
  • Sales volume peaks
  • Prices tend to drop due to the proliferation of competing products
  • Very profitable
  • Promotions, special pricing
  • Inventory control and analysis

4. Product Lifecycle Part 4

4.1. Decline and Withdrawal

As the product is becoming obsolete, eventually the product will be retired.

4.2     Characteristics

  • Sales decline
  • Prices drop further
  • Profits decline

5. Lifecycle Extension Strategies

As a product nears the end of its lifecycle, the company must decide what to do: withdraw the product altogether or extend the life cycle of the product through a number of strategies.

Product lifecycle extension strategies are marketing techniques designed to extend a product’s life cycle. If an organization decides to continue selling the product as it reaches saturation or enters the decline phase, there are a number of strategies that can be implemented:

  • Repackaging and new sizes: the appearance of the product can be crucial gaining a customer’s attention and developing interest
  • New formulas, different scents, flavors, colors
  • Additional features, additional product as a bundle bonus
  • Lower prices to maintain interest or liquidate surplus stock
  • New advertising campaigns
  • Altering the channel of distribution, such as online shops
  • Finding new markets – this may be locally, nationally or internationally.


6. Speed to Market

Part 1 is the stage where the innovating company is under the most pressure from a financial standpoint. The longer the period to develop a new product and get that product into the market, the greater the financial drain.

With this pressure on getting to market as quickly as possible, most SMEs will take the most expedient route. If that means not following any New Product Development procedure, then some organizations see that as a risk worth taking. The problem is, a lack of formal process usually results in project lateness because of poor communication, unclear expectations, redesign and redevelopment caused by mistakes caught too late, etc.

Don’t Count on QC Inspectors to Stop a Faulty Product Design

A QC inspection can be very useful in preventing a batch of defective or dangerous products from being shipped. But some importers seem to have excessive expectations as to what a QC inspector can do.

What is an inspection of finished products in a factory? It is the examination of these products’ characteristics against a set of specifications and/or an approved sample. Nothing more.

So the organized importer prepares a series of checkpoints that are as specific and detailed as possible, a list of potential defects, and an approved sample.

Now, what happens when the product’s design is sure to create problems? Is it the inspector’s job to catch that issue?

For example, let’s say a computer bag only has 3mm of padding as protection against shocks. This is insufficient for most consumers. But what if these bags are distributed in discount stores in India? It might be just what the buyer expects.

There are two implications:

  1. If the factory was allowed to make bags with such a thin padding protection (for example it was in your design files, or your organization approved samples with such a thin padding), there is a serious problem in your internal QA systems.
  2. If you employ your own inspectors and you train them to “see the products with a consumer’s eyes”, they might catch this issue. But you can’t complain to an inspection company (whose staff works for many different clients with different quality standards) to catch it.

I would also argue that it can be unhealthy for end-of-line inspectors to comment on product design, for the simple reason that they need to remain objective. If they advise a change in the product’s design, they are no longer purely independent observers.

That’s why the ISO 17020 standard warns to keep “the design, manufacture, supply, installation, purchase, ownership, use or maintenance of the items inspected” outside the scope of an inspection body.

And that’s why many buying offices have 2 separate teams:

  • A QA team for explaining a design to a supplier, reviewing samples, providing advice for corrections/improvement, writing down the specifications, and approving a “golden sample”.
  • A QC team for checking whether production conforms to the specifications and the golden sample.

For further reading on this topic, I suggest to read this article.

Tablets for QC Inspection: iPad, Android, or Windows?

As I wrote before, we have been working hard on developing a mobile app that allows our inspectors to work on a tablet. We got to a point where it works really well on iPad. But we have had to run tests on other types of tablets at the request of a few buying offices that are interested in using our app for their own inspectors.

I guess many people in the industry are planning to go the same route, and I thought a comparison of the 3 big alternatives (iPad, Android, and Windows tablets) would be interesting.

1. iOS tablets


  • Great hardware. Very stable.
  • iPad Mini (8.9’’ display) has a very good size factor. Not too small, not too large.
  • Easy to “lock” to a certain extent (by indicating that the user is less than 13) to prevent inspectors from installing many apps that slow the whole device.
  • Can open Excel, Word, and Powerpoint files. But advanced macros won’t be executed like on a Windows computer.


  • No flash, which means photos taken in a dark room are nearly worthless. Fortunately, there are many options for iPad- compatible LED flash accessories.
  • The entry-level iPad Mini is cheap, but Apple makes healthy margins for iPads with large memory and 3G capability.
  • Many more bugs (especially on the app management side) than I was expecting.
  • The “normal” iPad is a bit too large — it is nearly impossible to take a photo with one hand while holding the product in the other hand.

2. Android tablets


  • Very wide choice or hardware.
  • The Samsung Galaxy Tab line of tablets includes great tablets, but the best ones are as expensive as a good iPad or a a good Windows tablet.
  • Many tablets have the flash functionality.
  • Very attractive pricing on the low end (from 500 RMB).


  • This “open” OS is forking a lot. Who knows what Android tablets will look like in 5 years??
  • The hardware (and especially the battery) are not always reliable on low-end devices.
  • Several people told me Android is not great for opening Excel files. I still have to test the free Office viewer options (as offered by Samsung, Microsoft, etc.)

3. Windows tablets


  • These tablets work pretty much like a Windows laptop so the transition is minimal from the user perspective.
  • Many of these devices can be “converted” into a laptop. The keyboard is usually better than most wireless keyboards. This is important if your inspectors have to write a lot.
  • Perfect option for opening and even editing Excel, Powerpoint, or Word files.
  • The Microsoft Surface line of tablets is excellent.
  • There are now cheap Windows tablets on the market — it is nearly competitive with Android tablets sold under the same brands (Acer, Lenovo…).


  • I looked at all the Windows tablets in stores, and I didn’t see any with flash.
  • I feel most Windows tablets are a bit too large (over 10”) — it is nearly impossible to take a photo with one hand.
  • I had trouble finding the cheapest Windows tablets in stores.

What do you think? Any opinion or experience to share?