User can't delete some SFDC user accounts due to the following message:
Unable to delete staff number GEN01 for GEN01 as this is used in historic tables.
Please disable it instead of deleting.
Please complete the following steps to disable SFDC user accounts:
Log into Orchestrate and select Tools
SFDC Users
SFDC staff
Click Edit and untick enabled for each of the relevant users
Click Apply and OK to save the changes
Note: If the SFDC user account has process SFDC operations or downtime bookings, it cannot be deleted since the deletion conflicts with the Staff ID reference in SFDC table CommentBookings. Database referential integrity has to be maintained to avoid database corruption.