PM email notification

eAM Gurus,

I need your help in this client scenario and validate my solution :

Client wants an email notification sent out for every PM work order due. For e.g. if the PM schedule is set at 30 day frequency, then on the 29th day there needs to be an email notification for the user to run the "Generate work order" program so that the work order is created in unreleased status and then the authorized user can release the work order and assign it to a resource.

My solution : The above requirement cant be satisifed by standard  Oracle 11i functionalities. Hence a custom email notification has to be created.