"No" Should Not Be a Four-Letter Word

I wish I could remember where I first read it to give the proper attribution, but I've always found the following idea insightful: "If you create an organizational culture where the only 'right' answer is 'yes,' then that is the only answer that you will ever hear." Note that the author did not mean this as a badge of pride (i.e., you've created a "can-do" culture), but rather as a source of dysfunction and frustration. If you insist on agreement, you will hear "yes" even if the better, more truthful answer is "no."

For example, your boss asks if you can have the report ready at the end of this week rather than next week. If you say "yes" even though the likelihood of finishing it is small, then you have just set yourself up for failure. Worse, you may have actually set your boss up for failure as well if they now promise their boss that the report will be finished early. A reasonable "no" can be disappointing initially, but an unreasonable "yes" can really screw things up. 

Honest discussions also bring the possibility of compromise. For example, it may be possible to finish a report early with the understanding that other job duties will be pushed to the back burner for a while. Making trade-offs tangible can help put importance and urgency in perspective.

In an effective organization, people are not afraid to express concern about an idea, timeline, or approach. (Note that expressing concern about an idea, timelines, or approach is not the same thing as impugning the skill, motives, or reputation of the people involved.) Everyone has their own blind spots, so it is healthy to have an honest exchange of opinions when discussing the feasibility of a project or proposed change. Folks not involved in the minutiae of day to day tasks may not realize the impact of seemingly trivial changes or the amount of unseen work that goes into a "simple" product.