Epic Burndown Report or Chart is a tool used in Agile software development methodologies, specifically Scrum, to track the progress of work during an epic. An epic is a large user story or feature that typically spans multiple sprints. The chart or report is updated at the end of each sprint to show the progress of the team towards completing the work for the epic.

The x-axis of the chart or report represents the sprints, and the y-axis represents the amount of work remaining for the epic. Each sprint, the team updates the chart or report to show the amount of work remaining for the epic. As the team completes work, the line on the chart should trend downward, indicating that the team is making progress towards completing the work for the epic.

Here’s a detailed calculation for creating an Epic Burndown Chart:

1. Identify the total amount of work for the epic in hours or story points. This is typically represented on the y-axis of the chart.
2. On the first sprint, the total amount of work is plotted on the chart.
3. At the end of each sprint, the team updates the chart to reflect the remaining work for the epic. This is typically done by subtracting the completed work from the total amount of work.
4. The chart is updated at the end of each sprint and plotted on the x-axis by the sprints.
5. The ideal trend line is a diagonal line that starts at the total amount of work on the first sprint and ends at zero on the last sprint, indicating that the team completed all the work for the epic.
6. If the actual trend line deviates from the ideal trend line, it indicates that the team is not on track to complete the work for the epic on time, and it’s necessary to take action to get back on track.

The Epic Burndown Report or Chart can be created using a spreadsheet software, and it’s common to use a line chart to display the data. The chart can be shared with team members, stakeholders, and management to give them visibility into the progress of the epic and to identify any issues or obstacles that may be preventing the team from completing the work on time.