I suspect that they're talking about only buying a few finished assemblies from outside suppliers. It's kind of a bullshit metric though if you're contracting

I suspect that they're talking about only buying a few finished assemblies from outside suppliers. It's kind of a bullshit metric though if you're contracting with machine shops to make a bunch of different parts and then do nothing more than assemble them. Of course, where do you stop? If you buy billets, and machine those, does that count as in-house? Or do you have to buy raw ingots and turn those into billets or castings? Or do you need to operate a smelter and only buy raw ore? Or do you need to own the mine and the mining equipment? It's like XKCD says, everything is fractal. One guy's "in house" is another's "completely outsourced".