DAX to get SUM of columns above a certain record

[RGallagher320]

Hello - I am looking for a DAX measure that sums up the duration minutes for those records before and after the "Changeover" record. So I am looking for a measure that would be 25.91 (sums up the first two records for Producing and Discharge Backup prior to the "Changeover" record) and then another measure that would be 7.92 which is the Producing record after the Changeover one. I'm trying different stuff but can't quite get how to find the changeover record and then go from there. 

Any help would be awesome. Thank you!

[amitchandak]

@RGallagher320 ,Can you share sample data and sample output in table format? Or a sample pbix after removing sensitive data.