Descriptive Programming is a separate concept in QTP.
we can handle the Application by implementing the DP 
instead of OR.

Advantages of DP:
1 DP Script is reusable Script
2 we can modify the script easly compare to QTP Code.
3 we can write script without application in hands based on 
the properites of objects. 
4 DP is flexable for high performance of application 
compare to OR
5 DP script is very flexible for meet the object 
implementation problem in application.

QTP DP is a run-time processing of objects which are not 
located in QTP Object Repository.

Hi Nagaraj,
you are correct, We Using DP for the scripts whose objects 
not exsisted in Object Repository.
But here Questing is In What Cases ur going for DP instead 
of OR?
I think now u understnad the my Q?

In some scenarios, QTP will not able to recognize the 
objects in the appliation based on the description proivded 
in the objects repository. Say, mutilple objects in the OR 
has the same description and in these scenario QTP has the 
abiguity of doing the operation on the object and throws an 
error. To avoid this, we go fot the DP.

I agreed with the answer#4 but with some little 
clarification

When your application is also not ready at that time we 
will go for DP.
Regards
Alok

Adding to my above answer, here is another scenario where 
we can go for DP...say i have four webpages in my app's, 
and in each web page, say, i have OK and CANCEL buttons. 
Instead of adding this objects to OR at every page, i will 
create DP for this objects and use it where ever i need to 
do operation on it..........This way i can reduce the size 
of OR which inturn leverage's the performance of the QTP

Hi Rico you gave good examples.. Can you write Descriptive 
Programming for that scenario?