From your post, I gather that you may be in a very good or very bad situation when it comes to project management. If the project sponsors/stakeholders are voting something up or down, then you are lucky; and, other than the outcome, things are working as they should. If you are talking about the project team, then you are in a bad situation; and one has to ask where the hell is the project manager?

In any event, be sure that your critical input is in writing, and that you make your case in language that is understandable to the intended audience. You need to do this even if you are sure that your input will be ignored. The point is, you are creating a monument that you can point to during the postmortem, and make the case that you tried to point out the risk to the project. Do this without being a jerk, and maybe "they" will listen to you the next time. However, if the same thing keeps happening over and over, you are in a bad place; and you just need to move on . . .

Been listening to Stephen Covey and he talks about being influential by being influenced. And by listening to them. Actively listening to them. Stating their thoughts and ideas better than they can state them. I forget what he calls it, but it's basically reflecting their words back at them.

I've used this technique myself (although not in the scenario you're describing) and most people love being on the receiving end of someone actively listening to them. Really. Their eyes light up like kids' eyes at Christmas.

Covey talks about the technique working for many people who thought they didn't have a chance of convincing others -- individuals or groups -- to accept their ideas.

You sound pretty desperate. You might give that a shot.

BTW, it works great with kids too. Having that space to be heard really does a lot for people.

thanks, that looks like a nice solution.
I am not so desperate, it is only that i am smeling it to happen again as it has happened to me in the past and wanted to try something else this time.

thanks for the advice.

never have to deal with these people again. BTW I posted a way for you to do that, and it was deleted, good luck with your miserable life. Glad I’m not you.

@jason7, sorry to hear you’ve had to deal with that. I used to work for a company in which incorporating any bad ideas that came from a certain department was mandatory. That company no longer exists, for obvious reasons. At the time, the only way to handle the problem was as yucca suggests above: document, document, document (aka CYA). If we were lucky, someone in authority would review the milestones and catch the imminent disaster before it happened, or we were able to devise a way to prove the idea was a bad one (using focus groups in one case).

@noodle, you had it right: what Covey is talking about is called active listening.