Spans and Layers, the BMI of Organisational Design?

BMI (Body Mass index) is a calculation designed to identify if an individual is over-weight, or to be more precise is carrying too much fat.  The basic principle is that dividing your weight by the square of your height provides a BMI score, tall and thin scores best, wide and small scores worst.

Spans and layers of control is a modeling exercise, intended to determine the health of your organisational structure in terms of efficiency.  The popular construct of spans and layers being that (unlike BMI) narrow and tall is bad and wide and flat is considered the epitome of good health.

The England Rugby player Jonny Wilkinson stands 5’10” tall and weighs 189lbs, his BMI is 27.  According to the BMI scale Jonny is “overweight”.  Keith Richards of the Rolling Stones is the same height as Jonny (5’ 10”) but tips the scales at a lean mean 140lbs, his BMI is 20.  According to the BMI scale Keith is “healthy”.

Note: If you are reading this in America and have no idea who Jonny Wilkinson is, just think of Tony Romo with a posh English accent.

Therefore, if you were a personal trainer using BMI as your only reference point, you might decide that Jonny needed your attention more than Keith, an interesting outcome to a respected practical exercise.

The basic flaw in BMI is that it does not discriminate between muscle and fat in an individual, the basic flaw in spans and layers is that it also does not discriminate between muscle and fat in an organisational structure.  The muscle in any organisation is what makes it effective and productive.

Over the years, I have found myself in a number of bizarre conversations with people who have declared that the spans and layers of my team’s structure were, “too narrow or too deep”, but  funnily enough never that they were “too wide or “too shallow”.

I was once told to model my organisation on a principle of eight wide and four deep.  This exercise concluded with me responding that in order to craft such a vehicle, I would have to hire another forty-four people to fill in the blank spaces such a rigid mathematical exercise produced.  The response did not go down well, because it was part of a proposed efficiency (cost cutting) exercise.

There in lies the issue with spans and layers, it’s a sound sensible practice to model your organisation to be productive, just like it’s a good idea to have a model that tells you if you need to watch your weight.  However, as in the Jonny Wilkinson/ Keith Richard example, the game you are playing (or the business you are in) will determine the optimum shape you need in order to be your most productive.

The web is full of articles on the principle and implementation of spans and layers of control in businesses.  There are a plethora of “success” stories to be found on how company A flattened its structure, how company B widened theirs and how company C abandoned the principle altogether and decided just to form a big circle and all hold hands.  OK, I made that last bit up, but I bet that story is out there somewhere.

There are no right or wrong answers in determining the correct spans and layers within any business; every business is unique in one-way or another, as is every person.

So here’s my advice, before you let an organisational design consultant (including me) foist some best practice 8:1, 10:1 or n:1 model on you, make sure they understand the “muscle” your business needs to make your line-breaking runs.

Otherwise Keith might end up carrying your “corporate ball” after you’ve transferred Jonny to another team.