Favorite story I heard about voting was an anecdote relating to the flight computers on one of the Boing 7xx jets (probably the 757, but I don't know).

The story was that they were planning to fly with 3 computers, and that they would "vote" on important decisions.

The real trick was that they intended to build those computer with 3 separate teams, using clean room implementation (no coordinating with the other teams), and that they were going to use 3 separate CPU architectures, and even 3 different implementation languages.

As I understand it, they conceded on the language choice, they were all going to use the same language, but I don't know about the rest.

The goal was to avoid some catastrophic "unknown unknown" that might have crept into the implementation if they simply rolled out 3 copies of the same system.