Though limited but quite some options available to monitor Production in Microsoft Dynamics 365 Finance and Operations
To get more details pertaining to specific user error on D365FO screen, we need to get the activity ID and click on view raw logs in LCS. This can also be done by user as well. Copy the activity ID from D365FO screen and paste in the screen below:
Try to first see how production resources are being utilized and ensure there are no spikes in Memory, CPU and SQL
Restore production DB to sandbox and then run SQL queries/reports/statistics
Also in D365FO system admin could use database size.
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