Just use some judgement when asking.

If getting the answer in one minute saves you one hour, it is obviously good for the company to "waste" the other person's time.

You should definitely be careful not to waste the time of your coworkers. Just don't waste your own time either!

If everyone used their judgment this way, in a team of six, there are five others trying to save their own time and punishing the person who's worked to build up some knowledge.

This has to be fixed by ensuring that the bus factor improves and the knowledge is spread around more. I disagree that the solution is to let everyone interrupt the one who is trying to get stuff done.

> punishing the person who's worked to build up some knowledge. ... I disagree that the solution is to let everyone interrupt the one who is trying to get stuff done.

In essence we are talking about training new people and so this opinion seems selfish and unethical with respect to one's obligation to the firm.

The senior person should sacrifice some productivity until the new people are up to speed so that eventually the team has 5 senior people instead of one. If the new people are forced to figure out everything on their own, they might be only 5% as productive as they could be for perhaps their first 1-2 years. If the senior person simply gave up 20% of his time in order to answer questions for the first couple months, these 5 new guys likely would be closer to 80% productivity, representing a huge net gain in aggregate.

I only spoke against interruptions - not against spending time spreading knowledge. That, in fact, is in my good books as I already stated in my comment.

I guess I see these as 2 sides of the same coin; if the knowledge was properly spread via training and easy-to-use documentation, the junior developers would not need to interrupt much during the day.

>>> When I'm in the middle of something I don't want other people asking me questions or having "quick discussions."

Yeah, I get that, but most of us work in a team.