The „bus factor“ is a pars-pro-toto idiom. The „bus“ refers to any event that suddenly removes an important team member. This could be literally being hit by a

The „bus factor“ is a pars-pro-toto idiom. The „bus“ refers to any event that suddenly removes an important team member. This could be literally being hit by a bus (or SUV…), but could also be an illness, a move to another city, or simply a new position.