An argument over the best team size is as active as ever. As long as we are in broadly understood context of agile the starting point usually is 7 plus or minus 2 people, which was widely popularized along with Scrum. This, by the way, leaves pretty wide margin for the optimal team size. You can find more precise answers though.
It may be 6.
My rule of thumb is that no work team should have membership in the double digits (and my preferred size is six), since our research has shown that the number of performance problems a team encounters increases exponentially as team size increases.
Or maybe it is 4.6. By the way, does it mean that we need part-timers to chase the ideal? Oh well…
For the contrast Larry Maccherone reported at Lean Kanban North America 2013 that his quantitative research on data from nearly 10,000 teams showed that there’s no difference in productivity and quality in teams of 5-9 people and those of 10-12 people.
Yet another argument to the discussion: Anita Woolley’s research shows that collective intelligence, which I find a key ingredient of team effectiveness, raises along with a team size. It flattens out between 10 and 11 people.
But wait, didn’t Fred Brooks in his classic Mythical Man Month taught us that along with team size growth a number of communication paths grows exponentially? That would mean that for a team size the bigger means the worse.
This is confusing, isn’t it?
We are talking about the range between 4 and 12 already. I guess it wouldn’t take much of research to find sources that would broaden that range even more.
The tricky part, and one that often go unnoticed, is that when discussing the perfect team size we don’t ask the question: perfect for what?
Each of aforementioned sources focuses on a different angle. Be it performance issues, decision making, quality, productivity, problem solving or communication. Would optimizing any single one of these make a perfect team? I doubt it. Is it possible to optimize all of them at the same time? Well, it seems pretty unlikely. The numbers are just too far one from the other.
That’s not the fallacy of the perfect team size though. I know I’ve just introduced a complex equation with many variables to solve the ideal size problem. However, knowing our specific context we can use different weights for different parameters and solve the puzzle. Oh yes, it would be super-contextual and probably would be very hard to copy even for another team within the same organization. It doesn’t really matter though as the effort would be futile.
It doesn’t matter because the whole discussion is flawed unless we understand how our teams operate. While we typically assume that structural or hierarchical borders are what constitute a team it is a huge oversimplification.
An interesting thing happens when we observe organizations without fixed teams. One example may be Lunar Logic where people are assigned to ephemeral project teams and when a project is finished they move on to a next challenge. Another example may be Valve where someone who has an idea looks for others who are willing to develop the idea with them. These teams are even more unstructured as, at least in theory, people can come and go as they want.
Now, let’s think for a while how people work in such environments. Do they function only within a team they are currently a part of? To some point. As long as a discussion is related strictly to the matter of a project they likely keep it within a project team. However, given that the borders aren’t that strict it’s much easier to go beyond a team to look for new ideas or solutions when an issue is more general.
In other words people function in at least two different teams depending on a context. In Lunar, if I have 3 people in a project team this would be one entity they are part of. Another one would be 7 people who sit in the same room. Yet another one would be everyone within a range of a shout which is pretty much everyone in the company (yes, I know it’s easier with a small organization).
Depending on a specific situation people would organize themselves to optimize a key parameter to accomplish a task. When they are discussing the scope of new batch of work they would go to an empty room to optimize communication and focus. When they are solving issues they would have an open discussion and likely invite people from other projects to improve creativity and collective intelligence. When they want to make sure the quality stays high, they’d look for another pair (or pairs) of eyeballs to look at the code as very small teams seem to have worse quality than bigger ones.
Now, a big question: what team size we are talking about here actually?
Well, I told you. Three people. Except, when you look at a broader context, it isn’t much of answer, is it?
By the way in the context of Lunar Logic whenever I’m talking of teams I like to think of two layers of teams. One is a project team which typically is small. Two or three people per team aren’t a rare situation. Another layer is the company as a whole. In many cases we act as one big team. No hierarchy whatsoever of course helps a lot but that’s a different story. It means that we flexibly operate in 2-25 range in terms of a team size. I bet the ideal size, whatever it might be, is within this range.
Of course, an unstructured environment makes it easier to break the hierarchical borders. However, even in pretty structured organizations I know I see the same behaviors, except they are not that intensive.
The fallacy of ideal team size is that there is no such thing as the ideal team size. Instead of organizing people according to some sort of a magic number we should rather think of how to create an environment where people can easily adjust that size by themselves depending on the context.
Then the whole discussion of what’s the best size will simply be irrelevant.