A frequent problem in my D&D 5E group (4-6 players plus DM) is prolonged discussion about group actions. Upon reaching a point where the group has to make a decision, players will argue about the best approach, suggest new ideas, and try to reach consensus about the party’s action. If done well, this is a great opportunity for role playing and character interaction. However, I don’t think we’re doing it well.
Many times we find ourselves arguing at cross purposes and generally going around in circles for a long time until the party’s action is decided upon. Consensus may eventually be reached, but only after more than fifteen minutes of discussion, and it’s usually a poor kind of consensus — some players simply agree because they’re tired of arguing. These discussions are not hostile, nor due to a single player, but they’re still Not Fun.
I would like to identify some strategies that could alleviate this problem and stop the game getting derailed. These may involve techniques to apply at the time the discussion happens, or something that happens outside of gaming sessions. The strategies don't necessarily have to come from the TRPG world!
Example
Here’s an example: the party has to decide how they're going to pursue some leads. They could question some merchants, or go to their criminal contacts, or find another way altogether.
P1: “I say we question the merchants. We can be diplomatic about it.”
P2: “If the merchants recognise me, I could be in a lot of trouble. I’d rather start with our known contacts.”
P1: “That’ll close a few doors to us though. Word got around last time we did that.”
P3: “I say we go straight the the head of the chamber of commerce and confront them about this corruption!”
P2: “Okay, you can’t just walk up to someone that powerful and accuse them like that.”
P3: “Why not? It’s as good a strategy as any! We do have some clout around here!”
P1: “I really think we should talk to the merchants first.”
P2: “I still think that’s a bad idea.”
P3: “I’m telling you, a direct confrontation will force the issue!”
...and repeat from start about twenty times. No new information is being introduced, no player is ceding their position; in general there is no way to resolve this except by splitting the party or holding out until everyone bar one player gets bored.
Another example: the party has just made its way through a dungeon. They met an NPC (say, Dave), had a weird magicky vision of another world, and now there’s a ladder out.
P1: “Well, I’ve had enough of this dungeon. I start up the ladder.”
P2: “Wait, I want to go back and talk to Dave.”
P3: “No, I think we should leave. It’s not safe down here.”
P4: “I’m for leaving too.”
P5: “I want to investigate the area around where we had the vision. Is it magical?”
DM: “P1, you’re climbing the ladder? P2, what are you doing then?”
P1: “Yes, I’m climbing the ladder.”
P2: “Well I’m not. I start walking back…”
P5: “I’m going to cast detect magic!”
P2: “Dave is the most interesting person we've met down here. He may not be here for long!”
P3: “You had your chance to talk to Dave! We need to get patched up!”
...and on it goes. Again, no new information enters into the discussion, and it’s resolved only by exhaustion.
Problem to be solved
The specific bad outcomes that result from this that I would like to avoid are:
Too much talk that doesn’t progress the game. In the game world, barely anything might happen throughout an entire session.
Splitting the party. Eventually, one player might decide that they’ve heard enough and will simply tell the DM that they do something. Then the rest of the party decides they'll do a different thing. If it's of little consequence, it's not so bad (“you meet up tomorrow morning”), but often it means half the group waits while the DM talks to the other half until they can get back together.
Unfairness. A subset of the players will never really get to drive the group’s experience, because they would rather concede than drag out discussion.
The DM doesn’t get to do much. Their fun often comes from getting to entertain the players with their material and portrayal, and having the players surprise them in return. Both things grind to a halt when discussion drags out.
Answers
I would like to avoid answers based only on opinion and personal experience. A good, objective answer might include (some or all of):
Researched or authoritative sources. Examples: a blog post by a commercially successful TRPG game designer; an article in a publication affiliated with a successful RPG; an academic article on hosting community discussions; textbook techniques for running improvised performing arts sessions.
Applicability to TRPGs and D&D specifically (trivial if the source is about TRPGs). While committee standing orders are designed for structured discussion and decision making, they probably wouldn’t make for an enjoyable D&D session.
Demonstration. Is there a podcast that shows the DM handling players with this technique? A video that shows a theatre group being run in this format?
There may be other ways to qualify an answer, but remember that this site requires questions and answers to be generally applicable. There must be some way for people to judge how useful it will be in general, and not just to one particular group.