public interface EmployeeFactory
{
	Employee CreateEmployeeByType(EmployeeType employeeType);
}

public class EmployeeFactoryImpl : EmployeeFactory
{
	public Employee CreateEmployeeByType(EmployeeType type)
	{
		switch (type)
		{
			case EmployeeType.COMMISSIONED:
				return new CommissionedEmployee();
			case EmployeeType.HOURLY:
				return new HourlyEmployee();
			case EmployeeType.SALARIED:
				return new SalariedEmploye();
			default:
				throw new ArgumentOutOfRangeException("type");
		}
	}
}


public class CommissionedEmployee : Employee
{
	public override bool IsPayday() { throw new NotImplementedException(); }

	public override Money CalculatePay() { throw new NotImplementedException(); }

	public override void DeliverPay(Money pay) { throw new NotImplementedException(); }
}

public class HourlyEmployee : Employee…

public class SalariedEmploye : Employee…
}