From the Ask Tom mailbag –

Question:
I’ve been following your blog since you spoke at an event at our office in 2015. I see a lot of posts discussing timespan and organizational structures. What’s your view of “span of control” as it relates to organizational structures? The military has a 3-5 subordinate unit rule of thumb which makes sense for matters of life and death. Yet, I’ve seen organizations with people managing 20+ direct reports. This seems to be on the other end of spectrum and untenable not just from a managerial perspective but from a human/leadership perspective as well. Your thoughts?

Response:
I am not a military expert, so I am not certain of military rules of thumb related to span of control. Any readers familiar can jump in the comments.

Before I leap in, however, I want to re-frame the question. It is not a matter of management or control (even span of control), it is a matter of accountability. Here is my re-framed question – How many people can one manager be accountable for?

Elliott acknowledged a concept know as the Mutual Recognition Unit (MRU) which addressed your question. How many people can a single manager have on the team and remain an effective manager?

It depends. The maximum number Elliott placed was around 70. Beyond 70, it is likely the manager would begin to lose effectiveness. You have to remember the primary function of a manager is to bring value to the team’s problem solving and decision making. I can already see your skepticism through my internet connection.

For a manager to be effective with a team of 70, the work must be repetitive with low variability. The higher the variability in the work, the fewer allowable on the team.

Take a high-volume call center where customer support representatives respond to the same phone calls day after day. One supervisor may attend to teams as large as 70 before losing track.

Take a US Navy Seal team. How many on the team? I am thinking six. Why? Because the work is always variable with high levels of risk. One manager to a team of six.

So, it’s your organization. How do you assess the level of variability in the work? How much is repetitive? How much risk if the team gets it wrong? These questions will guide you to your answer.