You wait
until you find out theres no companies/people capable of building the equipment in your fabs
Wont matter then that theres optics guys, EE's and CS engineers who can do the design if theres no one who can make a 6 foot dia vacuum chamber complete with a purge system that includes behind the rubber gas seals..
I've found 1 person capable of replacing me in 5 years of various apprentices coming and going... and she's rather keen to get in on the programming the stuff rather than any shop floor "lets see if I can make a 600lb billet of 316 stainless into part of a chip fab line" type bollocks
Its just a sad state of affairs here that my last apprentice was paid near min wage, he gets 120quid a week more to stack shelves...... and my PFY's brother gets as much as I do for running a MacD shift...