"excluding addition in mass production by automobile producers"?

can you give me variants of translating this phrase??

"Tier 1" and "Tier 2" aren't official terms; they're more of a descriptive nature. They're also not exclusively used by the automotive industry, though that's probably where you're most likely to hear these terms used. The concept of "tier" doesn't reflect how big or important a company is; it mostly indicates who the end user of that company's product is.

Basically, if we stick with automotive manufacturing, at the top of the food chain are the original equipment manufacturers (OEMs), who are the name-brand car-makers, like General Motors, Toyota, Ford, Hyundai, Renault, etc.

A Tier 1 supplier would be a company who makes products specifically for one of the OEMs. That would be companies like Delphi or Dana or Johnson Controls who sell directly to an OEM.

Then you just move down the list. A Tier 2 supplier who be somebody selling products to Delphi. A Tier 3 supplier sells products to a Tier 2 (probably to a lot of Tier 2's), etc.

Из практики: я сталкивался именно с такой структурой