[numpad0]

Probably the first factory you walk into? That one would become the prime contractor that manage suppliers and subcontractors - I think those are the terms they use in multimillion aerospace and defense programs, but I believe the concepts are the same.

For aerospace programs, you sign a contract with e.g. Boeing for a 787 to be delivered 5 years for $500m, to be delivered to your company pilot at the Boeing Everett facility to be signed off and flown to accepting aircraft maintenance facility for your fleet. They then start dispatching fuselages and wings and parts to various aerospace kilo-corporates. They occasionally call you for confirmations and approvals for important items like engines and small overruns.

I guess the same in Shenzhen happens as a mostly-verbal order for a motor against Shenzhen Suchandsuch LLC in 3 days for $15k delivered the back of the factory on a shop table, with their chief machinist there to get you through the artifact and to help you with bubble wraps and duct tapes. But the overall structure is the same.