A Project Metric Join is when Project Metric list data is added to reports that also report on the Project Statement (e.g. the Template Projects - Projects Summary report contains a number of Project Metric Joins).
This means you can take advantage of the ability of the Project Metric's list to automatically gather and calculate project data and display this data in a Project Summary-based report. If a metric includes indicator icons, you can also opt to include these in the report.
Every metric can generate eight pieces of data that you can include:
Note: Project Metric and Project Statement join reporting is only supported in sites with one instance of a Metrics list. If you add a second or more Metrics list to a site, the Project Metric and Project Statement join reporting will not work as expected.
Only active metrics will supply data to the report. If a metric is marked as inactive, then no data from the metric will appear in the report.
You can also report directly on the Metrics list just like any other list.