Although Tesla's technology is commendable, the manufacturing process is not commendable, and Business Insider cited some Tesla employees (including those who have left and are still working titles).

The manufacturing difficulties at the Tesla Vermont plant stand in stark contrast to the new United Automotive Manufacturing Company (hereinafter referred to as "NUMMI"), a joint venture between Toyota and General Motors. From 1984 to 2010, NUMMI manufactured cars in this plant.

With NUMMI, Toyota "taught" GM the secrets of executing its production processes. Industry experts said that after Toyota installed its production system, the Vermont plant became one of the most well-known auto manufacturing plants in the United States. But after the economic crisis, General Motors went bankrupt and Toyota closed the plant, which was acquired by Tesla at a low price in 2010.

Tesla does not "inherit" Toyota's famous production methods. An interview with 42 people who have been working in Tesla since 2008 shows that it values production and technology, not quality and safety. Fifteen of them have worked at NUMMI and four have worked at Toyota.

Several interviewees who have worked at Tesla and NUMMI stated that although Tesla CEO Elon Musk was ambitious to revolutionize car manufacturing, the Vermont plant performed during the NUMMI period better.

According to five respondents who have worked at both Tesla and Toyota, one of the biggest differences between the two companies is that Tesla puts more emphasis on quantity than quality. Seven Tesla employees believe that the company is always more concerned with achieving production targets than ensuring the quality of its cars is flawless.

Dennis Cruz stepped down from Tesla last May due to a shoulder injury. "As a quality inspector, I was told that I can open and close one eye on the quality of the solder joints and mounts. Cars will also be sent for painting and then repaired with accessories. "

Tesla's quality control problems are not unnoticed by users.

Two respondents had worked at NUMMI for 20 years and said that 97% of NUMMI's cars were free of problems.

Toyota is known for product quality and production efficiency, and as a result has become one of the world's largest and most profitable car manufacturers. University of Michigan professor Jeffrey Liker said that over the years, Toyota has been imitated by almost all car manufacturers, but has never been surpassed.

Some interviewees have worked at both Tesla and NUMMI. They believe that Tesla turned a blind eye to Toyota's production methods and paid the price. The first three models produced at the Vermont plant-Model S, Model X, and Model 3-all suffered severe bounces.

Tesla employees said that the pursuit of production speed is part of the company's quality control problems. Some employees said that they would remain silent when they discovered the problem, worrying that pointing out the problem would cause the production line to stop, which runs counter to Toyota's production system.