Whenever I hear "this <person> is going to work on <project>" I edit my "bus factor of 1" wiki page.

Teams work on projects. People work on teams.

i know the term bus factor.
But i don't see, why singular people are not allowed to work on projects.

Why? Youre always trading off things within a project. And depending on the project size, you don't necessarily need it.
It would make it more important to document and backup projects, regardless of team size.

In an ideal world, we'd document everything, update our runbooks, etc.

In the practical world, this person becomes the subject matter expert, then gets pulled into every on-call, then bitches about having no time to document anything, then *BOOM* they buy a bus ticket away from the company because you've killed their morale ;)

I have a very nitpicky guideline regarding projects.

I need 3 people. Minimum.

These 3 people need to form a classical vote mechanism. There must not be a submissive person who blindly agrees to form consensus.

The reason? Simple. One does not like to argue with their self, especially not when tired and exhausted.

Discussion and compromise makes a project good - objectiveness being a requirement here. Realizing a single person cannot know it all and thus can't always make the best decisions is an important lesson learned.

(Includes myself, btw. I *have* glorious brain farts from time to time and it's nice when someone smells the stinky before its too late)

Solo projects seldomly end well. not only because of the lack of transfer of knowledge, but because a solo project will always be opinionated.

Why does it have to be called bus factor? Getting hit by a car is plenty, especially if it's a tank sized one.

It apparently goes back to a 1994 question asking what would happen to Python if its creator were hit by a bus. Gotta give credit where its due:

https://legacy.python.org/search/...