Engineering Change Orders: Manufacture in China like the Pros

Ruth Grace Wong
Jul 2, 2018 · 6 min read

Help your factory keep all their balls in the air amidst the turbulence of a fast-growing city

Working with our final assembly factory on a prototype of the Grobox. Pictured from front to back are Kevin, myself (Ruth), Eddie, Li Gong (the factory controls programming engineer) and Li Gong (the factory lead engineer)

“I’ve had to change this door twice,” says Jasmine, the indispensable owner of the sheet acrylic factory that we use. The heavy double doors separate her office space and her storage space. “With these new environmental and safety regulations, we’ve had multiple visits from inspectors. One told me the door had to open facing this way” — she points to the warehouse side — “so we changed it, but then the next inspector said it had to point back the other way.”

She’s had to make a few other changes too, like renovating her factory to separate the production space from the storage space. Thankfully, Jasmine is successful enough that she can absorb the surprise costs, but others are not so lucky.

Another factory, which provides 3D printed parts and CNC milled plastic for prototypes, has become totally swamped by orders. Many of the other prototyping factories nearby have closed down, unable to keep up with the changing regulations.

To make things worse, they had a blackout for a couple days and were unable to get any work done. The factory that we partner with for final assembly had ordered prototypes, and after flying to China we found out that our prototypes were going to be a few days late.

Eddie, our English-speaking contact, tells me: “Shenzhen proper doesn’t get blackouts anymore, but it’s normal for our factory here in Dongguan to have a few hours of blackout per week. It used to be a lot worse, too.”

Left: The safety inspectors have been coming around for a year — first once a week, and now once a month. Last week they said the gate on the elevator was unsafe so Jasmine had to take it out. The safety inspectors are doing their best but they don’t have any standards or guidelines to follow. Right: The door that’s been changed twice now has its lock on the outside of the office instead of the inside.

I’ve never been able to get good WiFi in the final assembly factory. They pass around files via USB stick and by printing them out with their black-and-white printer. The more I work with them, the more I realize that it’s actually pretty astounding that we haven’t had a major miscommunication.

Eddie has been doing a stellar job of making sure that any changes we want are actually implemented, whether we send them via email, WeChat, or phone call. When we’re at the factory, we ask the lead engineer in Mandarin:

“Li Gong, can you read English?”

“I can read the letters if you separate them,” he grins, “but I can’t read the words.” Li Gong reads what we send them via Google Translate, the only Google service available in China.

Having read The Hardware Hacker, by bunnie Huang, I’ve decided that it’s time to implement Engineering Change Orders (ECOs). A change order is just what it sounds like: a list of all the changes you’re ordering on your product, for the factory that produces them.

Bunnie talks about ECOs as a tool primarily used after you’ve already done costing and a purchase order. In my case, our factories actually provide a lot of engineer support, from fixing our CAD files, to programming the micro controller for the our control panel display to general manufacturability advice.

Given that our requested changes actually require some engineering design work on their part to implement, we are starting to use ECOs as a tool to stay organized, as we go back and forth with the factory on prototypes to converge to our golden sample.

Here’s a list of all the components of a good change order. I hope these practices will help you be more effective in assisting your factory with producing improved products.

In addition to the main list of changes, your change orders should have all the updated files related to your product, whether it’s CAD files or updated documentation on how the user interface is supposed to look. This way, if someone needs clarification on one of the changes, they can refer to the supporting documents.

In our case, we are going to have to ask Li Gong for the updated drawing files as part of the change order, but also for our own our records. With this heavily factory-supported style of product engineering, it’s easy for a factory engineer to make a design change to improve your product that you no longer have the most up-to-date drawings for, and you may not even know about.

If you plan to stay with the manufacturer for the long term, it’s not that big of a deal, but it is nice to be able to improve the design of your future products.

It’s good practice to write your change order simply, and then Google Translate it to Chinese, then back to English to see if it still makes sense. Similarly, changes are more clear with a screencap of a drawing (CAD or whatever you can muster) for the before and after to demonstrate what you mean in a language-agnostic way.

Despite these checks and balances, you can always be bitten by cultural factors that are impossible to predict. For example, our control panel has an up and down button, and everything worked as expected with the up and down button, except for setting the date.

On the date screen, the programmer had the buttons reversed. After some discussion we realized the problem. In Chinese up is shang (上) and down is xia (下), and on a physical calendar, the last week is positioned above the current week.

So, in Chinese, you would say shang ge xing qi (上个星期) — literally ‘up one week’ — to mean last week, and xia ge xing qi (下个星期) to mean next week. This is in contrast with the Western meaning where up and down would intuitively mean forward in time and backwards in time respectively.

It’s important to have a comprehensive testing protocol (in our case a checklist that we manually go through) to run on your prototypes to catch these kinds of errors.

We didn’t have the plastic parts of our prototype ready when we first got to China, so we went through testing with the control panel display, and found out that due to cultural differences, the up and down buttons didn’t work as expected for the date setting screen.

All of your documents should be dated with the same date the ECO was submitted, and include your company name, along with the name of the product (and version number/specific purchase order if that’s relevant).

The date will allow you to easily clarify whether or not someone is referring to the correct version of a document, especially if you’re collaborating remotely over the phone or by email.

Just like how you want to put your company name on any mail you’re sending to the factory so they don’t mix it up with other customers’ inventory, it’s nice to have your name on your documents to make it easier for people to keep things in order.

Finally, it’s important to properly communicate your change order. Sean ‘xobs’ Cross says: “One thing I’d like to mention that’s very tempting to do but will bite you in the end: WeChat ECOs. They’re very easy to make, but they’re person-to-person, and tend not to be documented elsewhere. I feel that’s a trap people might fall into because WeChat is so easy to use. After making a WeChat ECO, always follow up with email.”

Having gone to China and seen how much easier it is to contact people via WeChat than any other method, this is a great tip. Make sure there is proper documentation (i.e. email history) around you having sent the documentation, both to make sure everyone at the factory who needs to know has the information, and also for accountability in case there is any change over in staff.

Thanks to Jasmine, Li Gong, Eddie, and many others who make up the best factory partners anyone could hope for. Thanks to Mark and Kevin from Grobox for inviting me to be a part of their engineering organization. Thanks to bunnie and Sean ‘xobs’ Cross for technical review.


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