Best Practices for Protecting Electro-Mechanical Products

Kevin Howard, a packaging engineer from Packnomics, was kind enough to share his experiences regarding the protection of electro-mechanical products.

The rest of this article was written by Kevin.

My background is distribution packaging and testing, but these fields reach right into the product design space, especially for electromechanical products since there’s a direct tradeoff between product fragility and the amount of protective packaging required to survive distribution hazards.

The following thoughts are mostly derived from my work on electro-mechanical products, but may apply to many other manufactured products as well:

1. Why testing is essential — for product protection but also for cutting costs

Each and every component of a product should be well defined and specified. The manufacturer of these components should be able to prove they have employed the correct materials, that it’s sized correctly, and that it meets some kind of performance level(s).

Performance levels are different than material specs since they can quantitatively provide insights to the combination of materials employed and manufacturing quality. For instance, a correct paint may be applied and yet scuff off of a surface easily if the paint is mis-applied. Similarly, a box material may appear to be correct, but if the score lines are not set correctly and sub-par glue is used to hold it together, the box will fail.

A performance test is often easier to conduct than material tests and yet divulge potentially more pertinent information.

For instance, it takes lots of time and special equipment to dissect corrugated box material and attempt to measure the basis weight of each layer of paper used, measure the edge crush value of a small rectangular sample, and measure the burst value of a small sample.

In contrast, a compression test of the completed box immediately defines whether or not the combination of materials and manufacturing quality meet the minimum strength required to survive distribution. This kind of test is easily run and provides not only the essential information of whether the box meets a minimum standard, but also tells how much design margin is provided.

I have come across many examples where the user hadn’t realized their boxes were 2-5 times stronger than required, thus wasting lots of money with no apparent return.

2. When to test the product’s resistance

Many of the electro-mechanical products I’ve worked on have hundreds, if not thousands, of components. A valuable performance test for such products is a simple drop test, both for the bare product and for the packaged product.

Impact tests can be something as simple as dropping from a certain height onto a stiff surface (best to define this surface!), or using a more sophisticated method like a shock table, where one controls the input shock and the orientation of the product or package during that shock, though such equipment is fairly expensive.

If one knows that the bare product sustains no damage from some height at the beginning of production, then products in future runs should also demonstrate that level of ruggedness. If something breaks from an impact sooner than what the originally-approved product withstood, then it becomes clear very quickly that either a component or the assembly process has changed.

Kevin’s other articles are listed below:

AQL 2.5 Has Nothing to Do with the Number of Samples to Inspect

It seems like most suppliers and most buyers can only remember “AQL 2.5″ when it comes to the settings of QC inspections. Unfortunately, “Sampling as per AQL 2.5″ means nothing.

I am aware that “single sampling plan by attributes as per the ISO 2859-1 standard, normal severity, level II” is a bit difficult to remember. But that’s what determines the number of samples to pick.

Here is the table that matters:

How to read this table? 

If you follow my example, I assume your ‘lot size’ is comprised between 3,201 pcs and 10,000 pcs, and that your inspection level is ‘II’. Consequently, the code letter is “L”.

By contrast, the AQL, or Acceptance Quality Limits, are settings that indicate what number of defects is over the client’s tolerance. These settings do not impact the number of samples an inspector has to pick.

The second table comes into play:

How to read this table?

Your code letter is “L”, so you will have to draw 200 pcs randomly from the total lot size.

Besides, I assume you have set your AQL at 2.5% for major defects and 4.0% for minor defects. Therefore, here are the limits: the products are accepted if NO MORE than 10 products with major defects AND NO MORE than 14 products with minor defects are found.

I hope I clarified this subject. Hearing incorrect descriptions of inspection settings is a pet peeve of mine.

How Factory Audits, Inspections, and Lab Tests Fit Together

I am often asked questions such as “what is the difference between audits and inspections” or “why are lab tests necessary if you send an inspector”. In this article I will show how these three types of services fit together.

Let’s start with the service that is needed even before a purchase order is issued.

1. Factory audits

Auditors usually check a factory for capacity and reliability. They verify:

  • The facilities and equipment (can they make this product, and do they have the capacity to complete an order in a reasonable amount of time?)
  • The system (are there any dangerous practices? e.g. they never check the components from their suppliers.)
  • Basic information such as the size, the main products, etc. (did their salespeople tell their truth?)

For more details, see this infographic.

I always recommend a factory audit to importers who are about to work with a Chinese supplier. I could cite many cases where the buyer decided not to work with a supplier after seeing an audit report.

Weaknesses of audits

A factory might have perfect systems, workforce, and machines, but they might decide to cheat their customers. It often happens in China. Here are a few examples:

  • They may decide to subcontract production to another manufacturer that was not audited. That’s how Walmart Canada learned that their products were being made in the Tazreen factory that burned in 2012.
  • They may decide to use cheaper components that are not conform to the buyer’s requirements. That’s how Mattel found out that many of their toys were covered in lead paint, back in 2007.
  • They may alter their formal process, for example not maintaining storage temperature for food products.

A skilled auditor will spot some of these cases, especially if he conducts a process audit.

Unfortunately, auditing agencies in Asia typically hire auditors with no process knowledge. They see their job as verifying conformance to a checklist derived from a standard (ISO9001 for quality, ISO14001 for environment protection, and so on), and they focus on documents more than “real world” issues.

That’s why checking how each batch is made is important — that’s what inspections are used for.

2. Product inspections

Inspectors check the products for conformity to requirements. Inspections come into play more “down the pipe”. They check the results of the systems and processes that auditors check.

For most consumer goods, an inspection is usually composed of four steps (I am grossly simplifying):

  • Evaluating the quantity of goods, and picking samples
  • Checking the products against the client’s specifications and/or perfect sample
  • Looking for visual defects on all picked samples
  • Performing tests on a few samples

For more details, see this infographic.

There are very few cases where a product inspection is not necessary. If you purchase from China without checking your products (or appointing professionals to do it), you are taking serious risks. Once the products are shipped out and the order paid in full, buyers have no recourse.

Weaknesses of inspections:

  • When there are many different types of products (e.g. 20 types of valves, with 2,000 pcs per type, for a total of 40,000 pcs), performing an inspection on samples that are picked among each type of product is very expensive. It multiplies the time to spend on site, so that many man-days of work are needed.
  • Once production is finished, finding problems is very important — it avoids a very bad surprise to the buyer — but it does not solve the problems. That’s why, in many cases, inspections during production make sense. It acts as an early warning signal and allows the manufacturer to make adjustments while it is still possible.
  • Inspections typically take place in the factory or in a warehouse. In 99% of cases, the inspector comes to the products, not vice versa. It creates an obvious problem: the products often need to be tested, but some of those tests require devices/instruments that cannot be brought by the inspector. That’s why samples are often picked and sent to a testing laboratory.

Which brings us to the next part…

3. Laboratory testing

In a serious lab, a trained technician will respect exactly the right procedure (preparation in the right conditions, testing with properly-calibrated equipment…). However, laboratory tests are typically done on a few samples only — while hundreds of samples can theoretically be checked during an inspection.

Here are a couple of things to keep in mind when it comes to lab testing:

  • As the buyer, you need to choose the testing laboratory. If a supplier tells you “here are certificates/test reports corresponding to a previous batch” or “we can take care of the testing with a local laboratory which is fully accredited”, be careful. They are offering solutions that carry maximum risk for you. Buying a certificate from any lab is possible in China. And many ISO 17025 certified labs routinely give passed report without performing any test.
  • It is crucial that the samples picked for testing come from bulk production. Smart suppliers prepare a few nice samples that will pass the tests. To avoid this risk, send an inspector during production and ask her to pick samples and to send them to the lab of your choice.

I wrote the sequence to follow in this article.

Is something still unclear?

Why the Kunshan Zhongrong Blast is Only the Tip of the Iceberg

A severe accident took place last weekend in Kunshan (very close to Shanghai). Many good articles have covered it and exposed the facts. It was apparently triggered by poor ventilation that allowed dusk to accumulate and cause an explosion.

Over the past few years, very little attention has been given to the topic of worker safety in Chinese factories. The focus of buyers and journalists has been on the following elements:

  • Child labor (which is a rare occurrence, like in most communist countries), especially in Samsung’s supply chain.
  • Suicides, especially in Apple’s supply chain.
  • Excessive working hours (virtually all Chinese factories are above the maximum tolerated by the law).

This time General Motors is the customer. GM has made serious efforts in corporate social responsibility over the past years through programs that… did not aim at improving worker safety at their suppliers’ plants.

Why this accident is just the tip of the Iceberg

What about all the near-misses (similar circumstances across thousands of workshops, which fortunately did not explode)? They are impossible to count.

What about all the smaller accidents that didn’t make the news? They are impossible to count. When a worker is killed (and I would bet it happens several times a week in China’s factories), the employer gives about 1 million RMB to the family and the case is “closed”.

Even without this explosion, what was the life expectancy of the polishing operators? They were working in an environment saturated with thin aluminium dust particles. They could feel the metal in their mouth after a few hours of work, despite wearing a mask. I bet few would have lived beyond 60.

Sometimes we go to factories and gasp at the conditions in which workers do their job. We posted a few examples from a metal factory here.

Workers are unaware of the risks

Uneducated Chinese people are still unaware of many risks. (This is in no way particular to China, and many developing countries are in the same situation.)

For example, many people here don’t even know that smoking cigarettes every day increases their chances of dying of cancer. And, if you have come to China, you probably remember people crossing the street without looking at incoming traffic. Yes, these are the type of folks who work on the production floor of factories.

Some serious manufacturers are providing safety-related training to their workers. But they are still the exceptions. Most factory bosses hate the idea of spending on training for employees who might leave in a few weeks. They haven’t grasped that some are quitting precisely because no training is provided and because working conditions are tough.

There are so many accidents on construction sites that a Shenzhen employer recently decided to resort to provocation by posting a sign reading “if you die, someone else will sleep with your wife, beat your kid, and enjoy your compensation money”. Wow!

Why more and more accidents will make the news… Even though their proportion might decrease.

A few years ago, only NGOs like China Labor Watch and a few newspapers were exposing these cases. Now tens of photos are posted on Chinese social networks within minutes. Naturally, more of these accidents come out in the open.

Will the proportion of accidents go down? One can’t be sure. But the central government is taking action. They have already closed more than 200 metal factories in Jiangsu province. If they apply as much pressure on the local governments for worker safety as they have in the fight against pollution, there will be change.

Factory owners are reluctant to invest in better equipment — for example tables that suck the dust and evacuate it outside the building. They see it as comfort rather than necessity. But new government regulations, along with pressure from workers, will probably bring some change.

New requirements in China supply chains

More factory audits focusing on worker safety will probably be performed. Here are a few simple questions I have been advising buyers to look into:

- Are workers wearing appropriate PPE (personal protective equipment)?
- Are there fire hazards? Is fire prevention taken seriously? (Several tragedies were reported in Bangladesh over the past few years, and I am surprised there are not more accidents of that nature in China.)
- Has factory management done something about the major sources of danger to employees?

In parallel, I guess car manufacturers will apply more pressure for openness and transparency across the supply chain, and will help their key suppliers improve in that regard.

What do you see?

An Interesting Example of China Quality Scandal

The Changzhutan, a Chinese newpaper, just revealed one more food scandal. Most details have been translated by The Nanfang Insider into English.

1. The facts

Most street vendors sell beef and lamb meat-on-a-stick at the same price. It’s actually all beef meat. How is the beef taste masked? “By marinating and seasoning it with lamb flavoring agents”. Why? Because beef meat is much cheaper than lamb/sheep meat.

It will not come as a surprise to those who follow daily news here. For example, I read several stories about pork meat being “transformed” into beef meat on an industrial scale. But this story is interesting because several street vendors were interviewed. And they used excuses that are familiar to many importers…

2. The vendors’ justifications

They offered three types of justifications:

The “I don’t know the details so I am not guilty” defence:

The wholesaler told me this is lamb meat. If you were to ask me if this is really lamb meat, I couldn’t tell you.

The “only idiots really believe what we say” defence:

Calculate how much beef costs versus how much lamb costs.

The “everybody is dirty anyway” defence:

Everything has been altered; if it hasn’t been altered and doesn’t have the taste, who will want to eat it?

3. Lessons for foreign buyers

I think a few lessons from this example carry over to the international trade world.

Street vendors don’t risk much. They can disappear overnight. Same as most sourcing agents and many small trading companies.

There are many fly-by-night companies in China. Many of them are totally ruthless. The reason is, they can afford to. They have very little to lose. That’s why there are many scammers out there (yes, even among the Alibaba “Gold Suppliers”).

If a price is too good to be true, or if you don’t understand the economics of a deal, something bad is probably hidden in a closet.

As a buyer, try to evaluate the average market price for the product you are looking for. Any offer below the average price is suspect. Any offer 30% below the average is very, very suspect.

If the sub-supplier is at fault, your supplier will not accept any responsibility.

Most exporters do the assembly/finishing operations only. They purchase the components from sub-suppliers. And, in 98% of cases, they use whatever components they receive, for three reasons. First, their quality system is full of holes. Second, they usually don’t have time to wait for a new batch of components. Third, rejecting substandard components will cause the sub-supplier to “lose face”, so this is usually a big no-no.

In China, doing something shady is not a problem; only getting caught is a problem.

I have nothing against Chinese people in general, but one has to admit they live and work in a system that tends to encourage unethical behaviors. Therefore it is wise to be suspicious until proven wrong, rather than trusting people until proven wrong.

What do you think? Are there other lessons to learn from this food scandal?