BI Report - Assigned but not Completed

Summary

Report of training assigned but not yet completed

Content

We are trying to get a report of people who have been assigned a specific learning plan but have not yet completed it.  For some reason we haven't been able to figure out how to pull this data.  We can do everyone who has completed it or started it (incomplete) but not those who haven't even started.  Anyone been successful?  I feel like there must be something easy we are missing.