The gadget shows work progress as defined by time spent vs time estimated metrics.
2 main types of gadgets are available:
Overview report, which shows a general overview of all aggregate data (left gadget)
Data broken down by a certain configurable field (right gadget)
The overview dashboard gadget displays the time spent vs. actual time (which is calculated by adding spent time and the remaining estimate).
It also displays how many issues are created and how many are resolved.
Next, you can see the actual time for issues that also have the original time set vs the original estimated time.
This data is also used to calculate the original estimate error, using the following formula - original estimate time minus actual time (for issues that had original time set) divided by original estimate time.
A positive (green) estimation error value means that the original estimate was overestimated and tasks should finish earlier.
A negative (red) estimation error value means that the original estimate was underestimated and tasks will finish later.
If certain data is not set (e.g. original estimate), some fields will not be displayed.
The breakdown gadget displays the same information as the above Overview dashboard gadget, but this information is broken down by selected metric (e.g. assignee, project, sprint, or other).