Hi,
The requests could be handled by standard BizForm, notification could go to admin/employer, who can then use some custom module interface to proceed with the submitted data.
You could for example create a task for the vacation (
devnet.kentico.com/docs/devguide/project_management_managing_projects.htm).
Regrettably, there is no special feature for vacations in the
Intranet portal solution right now.
Our product managers considering this for future versions. It could be a nice feature.
Regards,
Zdenek