There is also logistics (again tons of messy bits), customer service (interacting with people), transportation (now this is probably the lowest hanging fruit - which is why everyone and their dog is chasing it).
Just of the top of my hat.. of course there is R&D (hard), design (hard), bureaucracy (bookkeeping, process management, etc. - easy in theory, not so much in practice) -- well, and all the other things that we humans do during a day of business.
We could also involve politics, government and philosophy - but that would probably be stretching it.
ps. I also suck at counting, so maybe that too.
I don't think transportation is very easy, it's just that the value is high and honestly, there is this trillion dollar asset (the nation's roadways) that companies are going to be able to leverage for a very low cost, which makes it appealing.