If the relevant administrator is set to "Application Approval Flow", it cannot be deleted.

If you have changed the "Approval flow", unapproved applications will be carried over to the administrator set for the new flow . Also, deleting the administrator does not affect the aggregated information or approved applications.

Impact of deleting an administrator

The administrator name will not be displayed in the time edit or application approval history. 

• Daily data > [Edit]> [Reference edit history]
• Settings > Admin> Admin settings > [edit history reference] of the target administrator
• Request approval > Confirmed> Details of target application

Supplements
If you want to leave the name of the retired administrator in the attendance editing and application approval history, do not delete the administrator and add a keyword that will be a landmark such as (retirement) to the administrator's name.