While rendering the heatmap, for each activity, Business Process Portal checks how many instances of that application have executed that activity.

For example, if there is a heatmap where the process instance status is completed, and workstep status is completed, then for each activity Business Process Portal calculates how many instances of that application completed that workstep. That value is used to find the fill color of that activity from the heatmap algorithm. The heatmap algorithm then finds out the bin range in which that value falls. If the value falls in one of the bin range values, then that bin’s associated fill color is used for those activities.

For example, if only five instances completed a particular workstep, say workstep1, then you can see which bin holds the value of five. In the above example, the 3rd bin, that is, bin[2] holds the value of five. Therefore, it uses the bin[2]’s fill color while drawing the activity.

The same logic is used where the Process Instance status is active, and workstep status is Activated, Completed or Suspended.

If a workstep is not in the state specified in the user's filtering criteria in any of the instances, then such a workstep is displayed in gray.

Using this heatmap diagram you can identify which activities are more frequently accessed, less frequently accessed, and those that are never accessed.