Span of Conrol
How many people can you manage effectively?
Although some textbooks will say you can effectively manage 5-7 employees, reputable ones will then qualify this with lengthy discussions on why this does not even qualify as a guideline.
Last week I had a client initiate a discussion about whether or not to create and staff a new director position; during the conversation, he told me he was not certain he needed the position as other than his own assistant, a receptionist, and the accounting and human resources managers, he only had four other direct reports, and they were all strong managers. For those counting, this adds to eight which is on the outside of the theoretical formula.
The reality is, one person can effectively manage many people if they are all the same profession, performing similar tasks, have similar competencies, and are working in the same location; but what about situations where each is a different profession with different roles, and at different work locations? For example a prison where you have security operations, food services, works and engineering, a hospital, and the variety of programs such as vocational trades training. (I have only scratched the surface of what is required to run a prison.)
Then there is the question of different levels of experience, abilities, and motivation; what if some managers were strong and others not? Would you advocate designing your organizational structure around the skills and abilities of your current staff compliment? If so, what if that changed tomorrow?
If you are overwhelmed with leading your organization and are considering changes, is the answer throwing more overhead at it? Or are there other options such as a realignment and/or merger of portfolios? Keep in mind manager strengths will vary over time, and when creating portfolios, you should group activities which make sense.