Registering absences are best handled on Cloud computing workflow systems (SaaS). When an employee can't leave the house because of illness or a cold, he/she can just click a few buttons of a smartphone and let the company know. The boss can approve the registering from outside the office. It'll automatically go to HR and accounting.
If you think BPM is a difficult theory, we suggest you start with a simple business process, like forms for registering absences. (BPM: Business Process Management)
<Tasks>
1. Register Absence, 2. Approve Absence, 3. Confirm Absence
[Absence Register <Revise> : "2a. Revise Absence Register" screen]
