Most business applications do not need to use class definition information. Code that uses class definition information is written by groups that write class libraries, application frameworks, and productivity tools.
Although your application might not include any code that uses class definition information, tools that you use for design, documentation, and class libraries will. These tools examine class definitions for your objects so that they can analyze your application and provide feedback to you.
Scenarios Class information might be used when developing:
A custom object browser
A tool that needs to know the objects of an application and their relationships
The purpose might be to document the application or to provide a logical way to select and work with the objects.
A CASE tool that deconstructs PowerBuilder objects, allows the user to redesign them, and reconstructs them
To do the reconstruction, the CASE tool needs both class definition information and a knowledge of PowerBuilder object source code syntax.
A class library in which objects need to determine the class associated with an instantiated object, or a script needs to know the ancestor of an object in order to make assumptions about available methods and variables