As always, there are lots of places where you can find all the 17 things you need to run a successful meeting. They’ll offer you tips on how to make sure everyone remains involved and engaged and how to keep the conversation on track. Maybe you’ll read about how walking meetings were one of the keys to Steve Jobs’ success or how 28 entrepreneurs have created great environments because they have a sand timer – salvaged from the game box they found in their parents’ attic – on the table to limit how long one person can talk.

While some of these may indeed be applicable to your situation, many won’t be. They all tend to be coming at the problem from the mindset that the setting for the meeting is a startup of some sort, or at least the “innovation” division the CEO just established to fend off competition.

Over the last 20 years I’ve been part of countless meetings and, in that time, I’ve found there’s really only one thing that determines how successful and productive that gathering will be:

Agreement at the outset on the desired outcome

I’m not saying that participants are deciding what the conclusion should be in advance of the meeting beginning. The conversation should go where it needs to go.

I mean that everyone needs to be on the same page in terms of what the next step after the meeting should be before it starts. “We’re coming out of this meeting with X.”

That kind of goal needs to be written at the top of the whiteboard in the room. If anyone diverges from that, the facilitator or organizer should (politely) head them off and ask if what they’re about to share is pertinent to arriving at X. If not, let’s table it for another time.

Time limits and other tricks aren’t bad ideas. Keeping meetings to 45 minutes is a solid one I’ve recently come into contact with and love it because it saves the inevitable “Sorry I’m late, the last meeting ran long” excuse.

Here’s the thing, though: It’s alright to be “that person” even if you’re not the leader of the meeting. Be the jerk who, 20 minutes in, says “Wait, what is it we want to come away with?” Get everyone’s attention and honk other people off, but get the meeting on track to actually be worth the time everyone is spending in the room. If someone wants to push back on you taking the initiative, let them. Ask them, though, how what you did took away from the value anyone derived? If the offense was more to their own ego and power ranking, you know what the real problem is.

A single meeting is usually just one small mile marker in a larger project timeline. Each one of those is a domino that needs to fall in order for the next one to do likewise. If you leave a meeting not sure if the domino has fallen, it probably hasn’t, and that could have implications for everything that comes later. It’s essential that someone – the leader or any random attendee – do what they can to make sure everyone in the room knows what the expectation is. Otherwise it really is just wasted, ineffective time.

Chris Thilk is a freelance writer and content strategist who lives in the Chicago suburbs.