Many companies manufacture in China in plants that are owned, staffed, and all engineering quality measures are managed and controlled by the parent company.
Many companies contract manufacturers in China to build their product (bid) and this is where quality issues can arise. Unlike the Counterfeit thread where companies are operating on the outer fringes of ethics and compliance and the law (international or us)
The company I work for has plants in 56 countries including China. The engineering, manufacturing and quality processes are identical. You can take a component from our plant in Romania and mate it with a US or PRC components and there is complete interchangeability, as they are all made to the same specification in our global standard. As do most ISO and TUV compliant companies do.
Perceptions of consumers is that if it is made in China or India or Vietnam it should be cheaper. The reality is our manufacturing facilities we have built in these countries in the last 30 years are more state of the art than any of our US or Canadian facilities.
