Timesheet Pay Rules Object Model Recommendation

We are refactoring the pay code rules part of our in house timesheet application.

Basically, employees have a weekly schedule in the system and they need to enter only their overtime, sick days, vacation etc. we then calculate and spread the hours in the appropriate pay codes.

So for each pay code we have the business rules, some calculations might be used by more than one pay code where the business rules makes one pay code dependent of the results of another.

I am trying to figure what object model/pattern would be best suited for this kind of scenario.

In my mind I have those objects (the business rules are in the code, they are not dynamically defined in a UI) :

• Employee
• Schedule
• Timesheet
• PayCode
• PayCode > PayCode 1
• PayCode > PayCode 2
• PayCode > PayCode ...