Stephen Few, who spoke at the QlikView conference in April, devised the bullet graph a few years ago. A QlikView customer used bullet graphs and sparklines and was very generous to allow QlikTech to post a working demo of their application. I’m going to build the bullet graphs from that app. You can download and dissect a QVW copy of that app from the QlikView demo website.
The bullet graph in QlikView is a bar chart overlayed on a gauge chart. The demo app uses a technique of aligning the targets on all the graphs to 100% of current year budget. The formula for the black line is current year actuals divided by current year budget. The darker gauge section shows prior year actuals over current year budget.
This technique has several advantages:
- Because PY and CY actuals are both divided by CY budget, they are still in harmony. You can visually see that current year sales is significantly less than last year’s sales.
- Actual divided by Budget unifies many measures with wildly different scales, making chart maintenance easier without hurting accuracy.
- Without this technique, you would need to write expressions for the gauge chart expression, and maximum values for bar and gauge charts. With this technique, they are 1 and 1.5.
- There is additional context in answering the question, “If we were repeating last year’s performance, would we be beating our budget, and by how much?”
I hope you’ve enjoyed this tour through bullet graphs. Take a look at the demo app for sparklines in action as well.