Hai,
 
According to me 
when ever deft fixes are done set of releated test cases 
need to be run on that one and check the the bug is fixed r 
not.

Hai sujatha what u said is correct but this is not a full 
answer.

Regression testing will be conducted after any bug fixed
or any functionality changed.

During defect fixing procedure some part of coding may be 
changed or functionality may be manipulated.In this case 
the old testcases will be updated or completely re written 
according to new features of the application where bug 
fixed area.

Here  possible areas
 are old test cases will be executed as usual
 or some new testcases will be added to existing testcases
 or some testcases may be deleted.

Any one of the situation may be arised.

So try to understand subject indeep

if you still have any doubt plz mail me 
At: rajendra_penumalli@yahoo.com 
or call me :9885162742(hyderabad)

Hi,

Regression testing means checking the reported 
functionality and its dependents. so we need to select the 
test cases to test both the cases.

TC's will be prepard based on the FRD's(Functional 
Requirement Documents). so changing TC's will comes under 
CR (Change Request) process.

regression testing will be conducted after development team 
releases modified build when test engineers find any 
mismatches between expected and actual values in build.

some times the small changes in coding can have serious 
effects on other areas of the s/w,with out development team 
concern.so a test engineer has to know wether the changes 
in s/w coding impact others areas of s/w,for this he has to 
conduct regression testing using previous test cases ensure 
that defect has removed the defect and remainig 
fnctionality same as previous(customer expected).

selecting test cases is depend on severity of the defect as 
follows:

if defect is high severity defect we have conduct 
                 all p0->high priority
                 all p1->medium priority
                 care fully selected p2->low priority
test cases for regression testing 

if defect is medium severity defect we have conduct 
                 all p0->high priority
                 care fully selected p1->medium priority
                 care fully selected p2->low priority
test cases for regression testing 

if defect is high severity defect we have conduct 
                 care fully selected p0->high priority
                 care fully selected p1->medium priority
                 care fully selected p2->low priority
test cases for regression testing

if any suggestions writw to me
gvikram_g@rediffmail.com
Vikram G

You Should answer<

I performed Regression Testing by both Manual and Automation,
by using Functional Testing tools like WinRunner , QTP.
And i run the same test cases which were used previously
before fixing the Bug/Defect was fixed, to make sure that
faults have not been introduced /uncover as a result of
changes made after fixing the defect.

Test cases includes
1. Fixed defects related test cases
2. Test cases related directly/indirectly to the affected 
functionality.