Best practice for "Portal Appplication in Maintenance"message ?

Hi,

I was wondering how you deal with portal applications that go "in maintenance". We now have multiple application area's (HR/PM/CO) integrated in our portal with own developed applications and I was wondering what the best option is if not the entire portal (for portal maintenance) goes down, but you just want to show for example a message "portal application down for maintenance" only for a certain application in the portal

- Do you change the role in which the application under maintenance is and assign it a page with the 'maintenance message'

- ...

Regards,

Igor