Without more detail about the business rules involved, kind of hard to state specifically, but here's an example:
Within the company, you have Employee, which would be your primary class. Derived from that might be Hourly and Salary, each of which have a different method for calculating wages. They might even be further derived into StraightHourly, HourlyWithCommission, StraightSalary and SalaryWithBonus, each of which have separate methods for calculating wage. The hourly employees would have factors such as overtime, shift differential and the like that don't apply to salaried.