Following is information about how to create a clean inheritance model and minimize problems when code is upgraded:

• Each class must have a single public construction method unless the class is abstract. If no initialization is required, use a static construct method. Otherwise, use a static new… method (the default constructor (new method) for the class should be protected).

• Each class should have at least one static construct method method.

• Each class should have at least one static new… method.

• Each class should have a new method (the default constructor). This method should be protected.

• Create accessor methods to get and set class variables.

• Create init methods to carry out any specialized initialization tasks that should be carried out after instantiation.