Problem Statement

In this example, we are going to represent the relationships between several classes of staff members of a company.

Some staff are paid employees. They have a social security number and a payrate in addition to name, address and phone.

There are also volunteers. The volunteers have a name, address and phone.

The paid employees fall into two categories. The executive employees have a name, address and phone and a bonus value.

Hourly employees have a name, address and phone and the number of hours worked.

Our problem is to represent a collection of the staff members and calculate the pay of the staff.