This morning a business intelligence consultant from Finland, Janne Pyykkö, posted an example of a Gantt Chart that he created with Excel that uses a heatmap approach to display quantitative values along the timelines, such as the number of hours worked. This brings the Gantt Chart to life with additional information, which allows you to see patterns that often remained buried in the data. Janne’s example points out one of the useful visualization features that was added to the latest version of Excel: the ability to encode quantitative values as color in spreadsheet cells. You can see a full explanation of Janne’s example at his Blog and read the discussion surrounding it in my Discussion Forum.
Here’s a picture to whet your appetite:
In this example, varying intensities of blue represent the hours worked per week for individual projects. The row at the bottom uses varying intensities of red to summarize the hours worked for all the projects. As you can see, this makes it easy to see the varying use of human resources on projects through time. The point isn’t to precisely compare the hours worked from one week to the next, but to view the pattern of change through time and to spot exceptions (for example, extreme values on either end of the scale).