An example: Borland marketed Pascal and later C compilers. (Ok, sorry--from the deep dark past.) They outsourced both pieces of technology. So you might think that this is an example of outsourcing core competency.
But their core competency was Marketing--Phillipe Kahn, during that period had glow-in-the-dark PR.
(Incidentally, the technological genius behind both products was none other than Anders Hejlsberg.)
So, maybe their core is not product design at all - maybe their core is product concept and product selection. They choose a product type they want, develop the initial concept far enough along to pass it off to the industrial designer who models it - then its contracted out to low-bid/low-cost (presumabley previously used) plastic fab in china.
Seems like a really good model when you have very simple, typically single-digit-materials, products.
I've never understood how they made that work, but obviously it is a strategy that has worked well for them.