Microsoft recently released work item reporting capabilities in the Visual Studio Online Power BI Connector. As a continuation of the new release, Microsoft has announced the general availability of trend and rollup reporting capabilities. You will be able to create sprint burndown charts based on story points, effort, size or remaining work. Hence, you will be able to trend any data in the model over time.
The rollup capability enables you to provide summary counts of work items in different states under epics, features or stories. The rollup counts faciliates you to retrieve a count of estimated, completed or remaining work.
Microsoft has discontinued the out of the box report to provide a more complete view of your data including a new Open Bug Status report page with bug trends.
If you have already connected to Visual Studio Online, you should recreate the connection to take advantage of the new model. Microsoft will release additional documentation in the upcoming week which examines the functionality of the model in detail. Moreover, the documentation will also address the anomalies which developers faced as a result of the model design.