[beambot]

A labmate of mine recently shared his term for this [1]: "Bus Factor" -- as in, the number of people who could be hit by a bus and still have the team / company / project function.

With a single-person company, the bus factor is essentially zero... unless you're a master of automation.

[1] Though he said it was common among his peers in Austria.

[n3rdy]

Another term used in this context is "single point of failure".

For those who can be control freaks with their businesses, this is one of those show stopper risks that creep up on you.