Learn from Startups: Quality Control in Device Manufacturing - Lemberg Solutions
8 minutes

Learn from Startups: Quality Control in Device Manufacturing

You might remember the issues Samsung had with the Galaxy Note 7 in 2016. After the release, they found a critical manufacturing defect in some devices. This defect caused Note 7 batteries to overheat and catch fire. In under three months, Samsung stopped selling and producing Note 7 devices worldwide. 

Due to a single defective batch, Samsung lost billions of dollars on designing, manufacturing, and marketing the Galaxy Note 7. Their mistake should be your lesson. If you want to deliver safe devices that work as intended, make regular, consistent and independent quality control (QC) an integral part of manufacturing. 

We learned about manufacturing quality electronics from LaMetric and Doppel, successful Kickstarter-funded startups. To sum up their experience, there are four distinct approaches to quality control. You can choose one or combine a few to build a thorough quality control system. The end goal should be to test the quality of hardware and software as well as the functionality of each device. 

Approach #1: Rely on factory quality control

Most factories offer to test products and confirm their quality in writing. Relying on these services alone is risky: the factory profit depends on whether you accept a batch or not.

It doesn't mean you shouldn't pay attention to the factory QC. On the contrary, there are a few steps you can take to prevent manufacturing flaws. 

First, involve as many people as you can:

  • Talk to the engineers. They are the only ones to know what the factory machines can and will do. Engineers might help you set up manufacturing that avoids most issues by design. This won't be enough for QC, but it's a good place to start.
  • Explain your expectations to QC and line managers. They will have a direct impact on the daily production of your order, and you need them to know what you are looking for. 
  • Have clear, open discussions with factory managers. They will be signing off on quality and enforcing your expectations when you're not there. 
  • Communicate with the salespeople, be polite and reserved. They control the price you will be paying, and you need to stay on their good side. But do keep in mind that usually they are unaware of the actual processes at the factory. 

Then, negotiate the quality terms. Specify every standard you can imagine, and go in as much detail as possible: what the final product has to look like, how the factory has to pack it, what should go into the box, etc. 

But keep it simple and mind the language barrier:

  • Use photos, technical drawings, well-translated written instructions 
  • If you can, provide operators with approved physical samples. 

And under no circumstances vary from the standards and dates in your contract. Do it once, and you might as well start looking for a new factory. 

Large factories (e.g. ones that assemble for Apple) have means for thoroughly testing devices. But they also tend to be more expensive to hire and are stricter about changes in device designs and components. By contrast, small and mid-sized factories are more affordable and flexible but have fewer means for quality control. 

As a startup, you might be unable to hire a large manufacturer. But you don’t want to sacrifice product quality either. Which is why you should combine factory QC with other means of independent quality control. 

Pros and cons of relying on factory testing

Approach #2: Hire third-party inspectors

You can hire local inspectors to carry out random quality checks. These inspectors will come to the factory, select a number of devices, and check them for defects. The selection size will depend on the batch size and the level of QC you’re going for. 

If they find any defects in the selection, you can choose to discard the entire batch. The factory will have to produce a new one at its own expense. 

This approach sounds good on paper, but it comes with two caveats: 

  1. The quality of a handful of devices doesn't guarantee the quality of all devices. Remember, not all Galaxy Note 7s had defective batteries. 
  2. Human inspectors are, well, human. They’re prone to mistakes, dishonesty, and other things that might cost you money. 

That’s why we don’t recommend this approach as the only means of quality control. But it does work well for verifying the quality of product appearance and packaging. You can hire inspectors to check that devices don’t have external defects and come with all the necessary accessories.   

Pros and cons of hiring third-party inspectors

Approach #3: Send an employee to the factory

You might consider sending one of your employees to oversee production quality at the factory. This strategy will help you understand what mass production is and how you can control its quality.

LaMetric were successful with this approach when they started mass-producing LaMetric Time. By sending one of their co-founders to Shenzhen, the startup learned the ins and outs of electronics manufacturing in China. This knowledge later helped them refine their product and design a more efficient, automated quality control system. 

Pros and cons of having employee at the factory

Approach #4: Build an automated quality control system

LaMetric's quality control system is computer software operated by factory workers. It combines automated and semi-automated tests and a logging system. 

To start, the startup generates and assigns separate unique IDs to all devices and their circuit boards. This helps LaMetric ensure the quality of each device throughout production. 

For instance, if they notice a manufacturing flaw in one of the circuit boards, the factory has to repair it. The ID lets LaMetric see that the flawed board has, in fact, been removed from the assembly line, repaired, and tested again. This system seems simple, but it has helped the startup eliminate manufacturing flaws. 

LaMetric’s logging system also makes counterfeits impossible, preserving the company's intellectual property. Because only devices with LaMetric's unique IDs can connect to their server and user apps. 

The quality control itself has a total of four stages. Devices stay connected to the quality control system during the first three:

  1. Hardware. The QC system tests device components; it checks memory integrity and assembly quality. 
  2. Firmware. The QC prompts operators to press different device buttons to verify response accuracy.
  3. User firmware. The QC prompts operators to connect to devices from a smartphone. This way, they help the LaMetric team check how devices reply to commands from the user apps. 

The fourth stage ensures that devices are ready for shipment. The QC prompts operators to place packaged devices on a scale. A correctly packaged device should weigh 540 grams: Boxes that don't reach this mark might lack components and cannot be shipped to the customers. 

The level of care LaMetric puts into testing their devices is impressive. And it's possible only with automation: Human-based quality control can never be this meticulous and quick at the same time. 

Pros and cons of bbuilding custom quality control system

Doppel is another startup to have made great use of quality control automation. Doppel is a wrist wearable that uses silent vibrations to help wearers feel calm and focused. Users set up doppels from their smartphones and control them with gestures. To test this functionality, the Doppel team asked us to develop a lightweight Android application for quality control.  

Check out the Doppel's case study.

Doppel’s quality control process takes three steps:

  • First, the app tests the Bluetooth Low Energy (BLE) connection between a doppel and a smartphone. This stage verifies the security and integrity of BLE modules inside doppels.
  • The next stage checks doppel responsivity to control gestures. The app prompts testers to follow a sequence of control gestures to see that devices respond to them correctly. 
  • The third testing stage is optional; it’s meant for devices manufactured in-between firmware updates. This stage helps verify update integrity and maintain backwards compatibility.

Systems like LaMetric’s and Doppel’s test device hardware, software, and core functionality at once. Let’s see what’s behind each of these tests.

Essential tests to run on mass-produced electronics

Regardless of what quality control approach you set up, here’s a small checklist of tests to run on your device. 

Tests for devices

  • You should test device hardware to make sure it works. This includes testing compatibility with other devices, battery performance, and other core components. If necessary, test Wi-Fi, classic Bluetooth or Bluetooth Low Energy, and other connectivity features.
  • Test database integrity to ensure that devices record, store, and process data under various conditions. Data should stay intact during updates and device restarts.
  • Perform functional testing to ensure that all device features work as intended.
  • Test the load performance of products that connect to more than one device. This will help you ensure that your devices can handle many network connections well.
  • Test device security to ensure that no one can access data the device sends to the cloud and back. Security testing is especially vital for devices dealing with personally identifiable information (PII), which includes credit card data and medical records.


To deliver safe and functional consumer devices, integrate quality control into the manufacturing process. There are at least four approaches that you can combine to build an effective quality control system:

  • Accept written confirmation of quality control from the factory
  • Hire a third-party inspection company to test product quality at random
  • Send an employee to the factory to oversee assembly in person
  • Automate quality control with bespoke software

Regardless of the system setup, run a variety of tests to check the hardware, software, and functionality of each device. 

Leverage Lemberg expertise for superb quality control

Slavic Voitovych is a great person to talk with about your plans for bespoke quality control software. He can share our expertise and show you other impressive projects in our portfolio.

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