Hi Project Manager, Fast, Cheap, Good - Please Pick two.

Trade-offs are inevitable when you want make the better result in reality.

"We need it fast, under budget, and perfect."
Everyone knows it's impossible. Nobody says it.

Then, three months later:
The project is late, over budget, or broken.

You can't have everything. 

The worst project managers?
They promise all three.
Then they blame the team when it doesn't work.

PS. Do you think the project management triangle is still relevant?