My experience is mostly with purchasing component parts made to our drawings from outside countries.
I can say that buying preassembled product from overseas eventually resulted in quality deficiencies that then led to an incident with us disassembling and rebuilding all product before it could ship. I would be extremely cautious that your quality control, stocking plans, and payment terms would not leave you in this kind of pinch.
My company once worked with an overseas supplier that manufactured both the components and the basic final assembly. That supplier quickly and quietly produced an identical product that was made to our drawings and sold in-country where we had no legal recourse. Once that kind of proprietary data is out, it's gone forever so consider separating the assembly information from the component design details. At least that gives you a moment in time to inspect the components with your own peoples eyes before they get hidden and committed to an assembly.
(I have other stories about the senior managers who fell for that trick, one being the Sourcing VP who forwarded a new manufacturer's brochure depicting a product that looked very much like ours, asking if consider them as supplier. Imagine his shame when Engineering had to point out it *was* our product, and he was asking us to send our business to the supplier who ripped off our highly proprietary design?!! I say imagine because this person was wildly arrogant and stupid and had no shame.)
If you're supplying 100% of the components, that's a very good start. Take care that the commercial grade parts cannot be swapped out with lower-cost substitutions. Ensure the assemblers have highly accurate work instructions and the correct tools and are enabled with a process to support them when things don't happen as planned.
