Power Visualization Choices (Part 4)
Last week we discussed some common use cases for two advanced chart types: histogram and bullet chart. In this post, we'll introduce the Gantt chart and heat chart (also called heat map).
Most people think of Gantt charts as tools project managers use to track project tasks and resource dependencies. While this is a useful application, Gantt charts can also be used to compare all types of business activities in relation to time.
When to use:
- Project Schedule. Track deliverables, project schedules, and dependencies.
- Display things that occur over time. Show how your resources (people or things) are being used over time.
Make it shine:
- Add color. Changing the color of the bars, such as giving each staff or task type their own color, quickly informs viewers about key aspects of the variable.
- Combine the Gantt chart with other chart types. You can use dashboard actions to filter down your Gantt chart to discover new insights.
Figure 1: This visualization shows shipment methods and delivery timeframes for publication shipped by a fictional organization. The length of the bar indicates the shipment time. Not surprisingly, regular air shipment takes much longer than other methods for all publication types. Comparing express air to delivery truck method requires some closer analysis by publication and/or order date.
- Heat Map
Heat maps are a great way to compare data across two categories using color. The effect is to quickly see where the intersection of the related categories is strongest and weakest.
When to use it:
- Heat maps are a great way to show the relationship between two different dimensions, such as membership type and age.
Make it shine:
- Vary the size and color of the squares. Using a measure on the size or color of the squares will add more depth to your visualization.
- Use other shapes. Change things up on your visualization. Sometimes shapes other than squares can be more meaningful to your audience.
Figure 2: On this dashboard we can see the sales and profit of our Member Types by Age. The size of each box represents the totals sales. The color and the intensity represents the profit, with shades of red indicating losses. We can see we have a large amount of sales and profit coming from our 65+ age group. At the same time, we can see that sales to members aged 26-35 are unprofitable across all member types. This is a great starting point for further analysis on the health and performance of membership programs.
In the next installment, we'll discuss some additional advanced visualizations - the highlight table and tree map.