The Different Sampling Plans Contained in the ISO 2859 Series

The vast majority of inspectors follow the ISO 2859-1 standard. But about ISO 2859-2, -3, and so on?

The relationship between these parts is explained in ISO 2859-10:2006 (introduction to the ISO 2859 series of standards for sampling for inspection by attributes):

⎯ Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection

⎯ Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection

⎯ Part 3: Skip-lot sampling procedures

⎯ Part 4: Procedures for assessment of declared quality levels

⎯ Part 5: System of sequential sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection

⎯ Part 10: Introduction to the ISO 2859 series of attribute sampling standards

As I explained in this video, part 1 of ISO 2859 (based on the “AQL tables”) is not to be used systematically. It should be reserved for business with regular suppliers. The standard explains it this way:

ISO 2859-1 was developed primarily for the inspection of a continuing series of lots all originating from the same production or servicing process.

For one-shot orders, or for new suppliers, part 2 is to be used. The reason is, the switching rules can’t be used since there is not a regular flow of batches to inspect:

ISO 2859-2 provides sampling plans applicable for use when individual or isolated lots are to be sampled. These sampling plans are in many instances identical to those in ISO 2859-1.

Is it a big problem if part 1 (based on the AQL tables) is used in circumstances where part 2 is actually applicable? Not really.

Sampling plans in ISO 2859-1 may also be used for the inspection of lots in isolation, but in this case, the user is strongly advised to consult the operating characteristic curves to find a plan that will yield the desired protection.

When to use part 3, and check only random batches rather than all batches? For very good suppliers only:

ISO 2859-3 provides skip-lot procedures for use when the process quality is markedly superior to the AQL for a defined long period of delivery or observation.

And what about part 4?

ISO 2859-4 provides a procedure that may be used to verify a quality level that has been declared for some entity.

The procedures in ISO 2859-4 have been developed in response to the need for sampling procedures suitable for formal, systematic inspections such as reviews or audits.

And part 5, which is particularly complex?

ISO 2859-5 provides a method of establishing sequential sampling plans of discriminatory power essentially equivalent to that of corresponding plans of ISO 2859-1.

In conclusion, QC practitioners tend to make their job easy and simplify the rules to follow. I think it is, to a large extent, not a problem. The main issue is that very few people follow the switching rules (which influences the number of samples and/or the limits for nonconformities, based on a score earned by each manufacturer).

By the way, are you wondering what the difference is between “inspection by attributes” and “inspection by variable”? See The different types of sampling plans for QC inspections.

Checking a Product’s Intellectual Property Rights Before Buying

A reader asked me how to conduct due diligence relative to the intellectual property rights of the products offered by Chinese suppliers:

I am to sell accessories in a specific market. I have stumbled on many Alibaba listings where:

1. Product in question is a brand name
2. Product in question is under different (made up?) brand name
3. Product in question does not have brand

The problem here is when they don’t disclose the brand, or they show a different brand because you never know if that product’s design is registered. You never know unless you are aware of such brand producing such product. For example I am aware of iPhone and all counterfeits that look like iPhone but when it comes to some kitchen product which I have never used, then I can’t be sure.

Microplane zester/grater is an example. Microplane is actually a brand, not a feature, technique etc. and this one was easy to find on Google. But what if Google is not sufficient or does not give a clear idea of the situation?

Unless I know it’s a brand, I can’t know if the design is protected or even if the product has a patent. That’s why I am looking for a system, guide, or software that would make such research easier to follow, reduce the risks, and save time and energy.

This is an interesting problem. Many other buyers probably share this frustration. And I don’t know of any easy way of reducing such risks.

  • Checking if a brand is owned by another company is usually easy.
  • Checking if a patent has been registered is complicated and expensive. To make matters worse, some patents are only registered locally and not internationally.
  • I guess lawyers can help and check the issues of trademarks and copyrights.

Anybody has an idea?

Do Chinese Factories Really Migrate to Inland Provinces?

One of the very clear trends over the past 15 years in China has been the migration of exporting factories from the Pearl River Delta to the whole coast, and then (to a much lesser extent) to land-locked areas.

However, my prediction is that this migration trend will slow down considerably, and for a simple reason: in many industries, it makes more sense to be located within the existing cluster of competitors rather than far away from them.

First, let’s look at the exceptions — those industries for which production is very widespread. Here are few examples:

  • Wood furniture
  • Jeans (denim)
  • Steel

What is special about these exceptions? The source of materials is spread out, so the processing & assembly factories are also spread out.

In most industries, though, production is clustered around a city. Here are just a few examples:

  • Lighters in Wenzhou (80% of the world’s output, according to Financial Times)
  • Socks in Zhuji (a third of the world’s production in Datang district, according to Wikipedia)
  • Ceramics in Chaozhou
  • Printers and consumables in Zhuhai
  • Knives in Yangjiang
  • Electronics in Shenzhen and Dongguan
  • Stones in Xiamen

You will notice that all these clusters are all along the coast. The raw materials / components suppliers have set up factories close by and won’t move. Processing industries requiring heavy equipment can’t relocate inland easily!

Based on my company’s data, more than 90% of export-oriented production is still in the following coastal provinces: Guangdong, Zhejiang, Fujian, Jiangsu, and Shandong.

The real migration has been from South to North. For simple consumer goods, Zhejiang has nearly caught up with Guangdong, and Fujian and Jiangsu have also become major players.

On paper, relocating a factory to an inland province presents many advantages:

  • Lower wages and lower staff turnover (more local workforce)
  • Lower electricity cost
  • Lower price for buying or renting factory space
  • Less disruption around Chinese New Year
  • Welcoming local authorities
  • Closer to raw materials (e.g. wood in Guangxi province)

However, there are also many disadvantages:

  • Higher cost for getting components from coastal areas or overseas
  • Higher cost for getting finished products to port – can be higher than international freight
  • Much fewer skilled managers, engineers, maintenance and QC specialists, and production operators
  • Relocating a factory is a very strong one-off disruption
  • All relationships with the local government need to be built from scratch

Here is my conclusion on this trend:

  • Relocating to an inner province makes more sense in labor-intensive industries, and for those factories that plan to sell part of their output on the domestic market.
  • A very small proportion of existing factories will relocate.
  • Factories in Jiangxi, Anhui, Henan, Shanxi, etc. are mostly new operations.
  • Costs are rising everywhere! A bowl of noodle is cheaper in Shenzhen’s industrial areas than in Chengdu.

Do you agree?

Maturity of Manufacturing Areas in China

I noticed that inexperienced importers tend to look at obvious signals (prices, response times, quality of English…) when communicating with potential suppliers. But they often overlook the location of the factory.

The export manufacturing industry really emerged in China in the early 1980s in Shenzhen. For example, most office buildings that are in the Huaqiangbei area used to house manufacturing operations. Then the exporting factories went to Dongguan city, to the rest of Guangdong, to Zhejiang and Fujian… and so on.

What is pushing new factories further and further away? Labor availability and cost, as well as other factors.

The dynamic goes like this: as costs rise, many importers need to go to less mature areas. note that this strategy is more difficult in industries:

  • With final processing/assembly concentrated in one cluster
  • With raw material / components concentrated in one cluster
  • Dependent on particular engineering and production skills

Let’s look at the lingerie industry for example: production shifted from Foshan and Dongguan to Shantou, and from Shantou to Quanzhou. Shantou and Quanzhou are cheaper than the Ho Chi Minh area!

This industry has several clusters because the equipment is cheap and the skills necessary for simple productions can be learned fast.

If I am allowed a broad sweeping generalization, here is how I see things:

Area Pearl River Delta Zhejiang, Jiangsu, Fujian Other areas, mostly inland
Maturity ++ +-
Understanding of export customer requirements ++ +-
Number of engineers + -
Price level + +- -
Quality level + +- -

I often need to explain to my clients that, for many products, the Pearl River Delta is the best area for production thanks to the following attributes:

  • Wide range of component suppliers within 2 hours around the factory
  • Ability to source small batches (flexibility and speed)
  • Abundant skilled workforce
  • Access to excellent logistical infrastructure
  • Proximity to many potential customers (other manufacturers that buy parts)
  • Ease of attracting and retaining expats

Do you agree?