How to disable the auto-assign checkbox on the Issue without customizing?
You can disable the auto-assign checkbox on the issue component without customizing. This is done through Phire security. Navigate to: Phire Architect > Security Administration > Domain Security
Select the Role from which you want to take away the auto-assign checkbox.
Click the Permission List link next to your Domain.
Uncheck the “Override Auto Assignment” permission.
Note: If the user belongs to multiple roles, you need to make you take away the above permission from all the roles. If at least one role assigned to a user has this permission, then the auto-assign checkbox will still be enabled.