Why Experts say: Don't' Use Gauges on KPI Dashboards

Last Updated: Friday, October 12, 2012 by Johnathan Briggs

Adding a gauge to your KPI dashboards is a very contentious thing to do. Gauges are loved by people building dashboards but disliked by many performance consultants. Many KPI experts publish thousands of words on why you should never use a gauge in your KPI dashboards, and also why dashboard software vendors should not allow data to be visualised in a gauge (Take this one!).

Like all things in life it's not that black-and-white and there is a time to use a gauge and a time when it is less appropriate.

The rise of the gauge

Gauges are somewhat of a historic visual indicator that has graduated into the digital world, they used to be used to monitor machinery with analogue sensors and no ability to store any history other than in the user's memory. The most obvious gauge that we all think of is our car speedometer which fits very nicely in our grand analogue of a 'dashboard'.

Let's for a moment think about the speedometer in our car… We are driving along and glance down at the speedometer to determine if we are driving at the appropriate speed for the road we are on. You could say that the speed limit is our target and the value of the needle is our 'actual'.

I'm not sure how long speedometers have been on cars but it's obviously tens of years, at least. Over the generations, manufacturers have experimented with digital speedometers but ultimately they all return to the analogue needle which has made this type of gauge incredibly comfortable and recognisable to us. The speedometer works perfectly, so there is no need to change it. When I'm driving I only need to know my current speed I have no interest in what my speed was five minutes ago, nor do I need any more accurate measure of my acceleration or deceleration then I can feel with my own senses.

This is where our analogue should stop. Our metric of measuring speed in a car is radically different to almost every corporate metric or corporate key performance indicator that you may choose to measure and communicate.

Now let's consider a typical metric used by most businesses that they would normally be reported upon in some form of KPI dashboard. For example let's use "quantity of sales" as a metric to illustrate the number of units of our product that we sell every single month.

Again, let's imagine that we target one hundred units per month.

Now within our dashboard software we could take this KPI and add it to our dashboard as a gauge showing a really cool red zone if we are below target and the Green zone for when we are above target.

If you look at this gauge it simply tells us the current situation it does not tell us anything about the past or the general trend.

If our gauge shows that we are within target then we should all celebrate and be happy with our performance, however what if for the last five consecutive months the number of units that we have been selling has been progressively dropping? This should be ringing alarm bells and key managers should be looking carefully at what is going on. Our gauge tells us none of this until it's too late, we only know that something has gone wrong when we fail to meet target, by this point it's too late.

Traditional gauges look great, they empower the dashboard designer but they do not communicate as much information as they could within the square inches of your KPI dashboard that they take up.

Consider the simple but boring alternative - a time orientated chart showing a target.

It might not look as nice with fancy, glossy lighting effects but it communicates an awful lot more. This chart clearly shows us the current situation, it shows not only if we are on or off target but it can demonstrate the general trend so we can see if the numbers are moving in the right direction. By seeing this trend we can estimate the future and make decisions in advance of a problem occurring.

This is a far superior use of data visualisation than simply showing a list of gauges.

Re-engineering the gauge

Here at Target Dashboard we are faced with the gauge dilemma regularly. We know that people feel very comfortable and like to use gauges but at the same time there are always more superior alternatives that will communicate more clearly. Several years ago we set about re-engineering the gauge so that we could get the best of both worlds, the comfortable visualisation of a gauge but also something that communicated more trend information within the same space.

What we have produced are three different gauge designs all of which are based on the feedback of our users and looking at the best practices and best ideas from other dashboard designers.

In the gauge design below we have tried to maintain the appearance of a traditional gauge with a colour-coded target bezel. The gauge also shows beneath the last dozen recorded values and the target line so it's possible for the reader to have a clear idea of the trend direction. This creates the best of both worlds, a trend graph and a nice clear visual, colour-coded gauge.

This setting gauge design is very similar but we have used a thermometer style indicator which changes colour from red to green want to target has been met, again there are trend indicators.

The final gauge design is more digital and more modern. It clearly shows the actual value of our metric and also some derived information such as the percentage change from the previous month and how on or off target we are. Below are the last 12 recorded values along with a target line, but the bars in the chart have been colour-coded red or green so it is instantly clear if target has been met. Of all the gauge designs this particular design communicates the most information.

All of these gauge designs are built into Target Dashboard, so will take you just moments to add to your KPI dashboard. However, if you are not using Target Dashboard and building your own custom key performance indicator dashboard you are more than welcome to copy our gauge designs.

A gauge is not for every scenario, but with a little modernisation bringing it up-to-date we can still make it a very effective tool to communicate our KPI's on a dashboard. If you'd like some more information, our Dashboard Best Practice Guide has lots more information for implementing effective business management in a dashboard.