Earlier this month Pete Abilla wrote about effective team sizes in his newly redesigned Shmula blog. The idea is that generally small teams are more effective because communication is essential to team success and beyond a certain size effective communication in a team cannot be maintained. This would seem like common sense, and it would never have occured to me to pull out the maths, but Pete can drive his point home quantitatively with a well-placed equation and chart like no other:

His "two pizza rule" from Amazon.com is also a valuable reminder that if your team size is larger than can be fed by two pizzas, it is probably too big. We need another chart her perhaps to show the distribution of the effect pizza size by region of the country (deep dish versus thin crust) has on team effectiveness, as well as relative eating habits and appetite by region to determine how far those two pizzas will go.

In terms of the importance of team size, consider these rules of thumb we have learned from the standpoint of kaizen, TPS and lean operations:

- Kaizen teams should be between 5 and 10 people per team with one team leader. Larger teams may be split into smaller themed groups with sub-team leaders or co-leaders directing.

- Team size at Toyota is between 4 and 8 people per team leader depending on process, location and other variables that affect the level of support and training people will need.

- Breakout groups in training classes or workshops should be no more than 5 people in order to keep them from splintering off in side conversations

We can borrow a metaphor of a cowboy driving his herd of cattle across the plains. A smaller herd is much easier to keep together. As a few head of cattle begin to wander off at the edges, the cowboy can herd them back towards the middle. In the case of human beings, one would think that our superior intelligence and sophisticated communication methods would actually help us get back in alignment with the team (rejoin our herd) quicker, but often the opposite is true. We use our intelligence and communication skills to defend our position, or to try to bring the cowboy to our way of thinking. So it takes more time to persuade people. There is simply not enough time for a leader of a large team to be effective in bringing team members back in alignment as entropy sets in and the need for communication arises.

There is an expression "it's like herding cats". Cats are notoriously intelligent and independent and do not respond well to being told where to go or what to do. It can be difficult to bring a group of intelligent people together toward one way of thinking, or to get a team of lean six sigma consultants to follow a standard...

Pete writes about the origin of the words team and staff in the post Team or Staff? last December. This is a reminder that a team is made up of a group of people who share a goal, each have a role and know the rules. As Pete pointed out good communication helps establish and maintain these things. The larger the group the more difficult it becomes to maintain a common goal as perceptions of priorities or perspectives people have on particular aspects of the project begin to diverge.

A proper team leader to team member ratio is the key ingredient in making effective teams. Teams can only be as effective as they are united in a common goal, engaged in their role and working within the established rules. The team leader's job is to remind them of these things and to help them stay on track. Large teams can be good for gathering a wider range of ideas or analyzing matters more deeply and thoroughly, but when it comes to executing with urgency nothing beats a small, focused team.