The state we’re in

Helping colleagues (who aren’t interested in tech) understand the health of an IT estate.

A few people (well, a couple) have asked me how I put together this chart summarising the state of our IT estate, so I thought I’d write something I could point to.

Heavily fictionalised version of a treemap showing system status across an organisation


In my early months in a new role, I learned a lot about my new organisation and our various services and systems. There was lots of demand for new stuff, but I soon became aware that we also needed urgently to address some legacy issues. I needed to communicate this to my colleagues in the senior team, but I knew that they had a lot on their plates. I didn’t want to burden them with a huge paper describing the status of our systems, but I did want them to get a feel for what we were dealing with and how their issues related to other peoples’.

What’s the user need?

I turned the general info covered in the why paragraph into an explicit user need.

(A user need, is a way of expressing a requirement (for a service or product) that centres the needs of the potential user. It usually takes the form “As a [type of person/user], I need to [what does the person need to do?] so that [why does the person need to do that?]”)

So in this case: As a senior manager, I need to understand the overall status of our applications and infrastructure so that I can make informed decisions about priorities for action.

The solution should:

  • Group systems by business area to give context on each element
  • Show relative business impact of each system.
  • Show status/ fitness-for-purpose of each system.
  • Be viewable at a glance


I used the Tree Map chart type in Google sheets. (Recent versions of Excel have this chart type too, but I couldn’t see a way of assigning colour to each block)

This uses a row for each block on the chart. Each row includes:

  • System
  • Business Area
  • Impact
  • Status

System: Choosing the right level of granularity was important here. Using wording that was meaningful to the people reading it.

Business Area: This is the parent category. All values (except the ‘all systems’ header) have a parent system. These values must all appear in the system column too.

Impact: This determines the size of each block. Set to reflect the relative importance of each system. This wasn’t especially scientific:

1 = We could struggle on without it for a while

5 = Pretty important, used by lots of people or a critical function

10 = Totally vital, we’d fall apart without it.

Status/Fitness for purpose: Again this was pretty subjective, with the score representing a combination of how well the system meets user and business needs with its current level of risk.

1 = Fit for purpose, everything is fine and is likely to remain so for a while

3 = It’s working but it’s not great and/or it won’t stay working for long

5 = It’s terrible or broken or generally on fire (or will be in the very near future)

The chart allows you to assign 3 colours: Min, midpoint and max values. I wanted to have a RAYG type scale so I chose (surprise!) red, yellow and green.

You can make a copy of the sheet here.

Did it work?

Yes! People immediately engaged with the info presented. We were soon having an informed discussion of priorities across business areas, which is what I had hoped to achieve.