The best part was, everyone was involved in the whole 'stack'. The engineering group I worked with handled QA, but also travelled downstairs regularly to help with manufacturing procedures. We watched assemblers and proposed design changes to make their jobs easier. The process created a virtuous cycle where the initial person laying out the board knew what kind of headers would be hard to connect in which enclosure (for example), and as a result the quality was very high while being competitive on cost.
I think an assembly process like that would have helped, for example, with the teething problems experienced by the Jawbone Up.