I am a graduate student working on rules based systems in design. I had a very fundamental (theoretical) question
on rules usage and would appreciate if you could be so kind as to help.
Consider a hypothetical  university application that has the following objects:
GradStudentRecord (which contains details such as GPA etc.)
GIven the above(and based on the drools docs I have read so far)
I can write a rule as:
when GradStudent.Record.GPA > 3  then student.standing = good
So far everything is okay.
Now consider the case where the University decides to have PhD Students.
Note that there are no PhDStudent objects in the application yet but
I wish to have a rule such as:
when PhDStudentRecord.GPA > 3.5  then student.standing = good
Does the above scenario mean that I would have to code the application
and add an extra PhDStudent object before I can write a rule ?
In other words, is the following proposition true?
Proposition: if there are N objects in an application, and I wish to use
JBoss rules then the rule can be written only "in terms" of the N objects.
If there is a rule to be written for a new  (K+1)th object, I would have to first code
that new object in the application and then write the rule.
I would appreciate if anyone could validate my thoughts above.
Michigan Tech.