The document discusses regression testing, which is essential when software modifications occur, such as requirement changes or bug fixes. It outlines various techniques like 'retest all,' 'regression test selection,' and 'test case prioritization,' emphasizing their pros and cons. It also highlights challenges in managing large test suites and the importance of maintaining a stable testing environment.

1. Regression Testing
HARSH VERMA
JIMS VK

2. Meaning.
Regression means errors that occurs due to
some action or activities in a system . In IT
regression means return of a bug.

4. When to do it
Regression testing is required when there is a:-
 Change in requirement and code is modified
according to the requirement.
 New feature is added.
 Performance issue fix.
 Detect fixing.

5. Techniques of Regression Testing
Hybrid
Retest all
Test case prioritization
Regression test selection

6. Techniques
 Retest all :-
under this technique checks all the test cases on the
current program to check its integrity. Though it is
expensive as it needs to re-run all the cases, it ensures
that there are no errors because of the modified code.
 Regression test selection :-
under this technique runs a part of the test
suite (owing to the cost of retest all) if cost of
selecting the part of test suite is less than retest all
technique

7. Techniques
Test case prioritization :-
Prioritize the test cases so as to increase a test suite's rate of fault detection.
Test case prioritization techniques schedule test cases so that the test cases
that are higher in priority are executed before the test cases that have a lesser
priority.
Types of test case prioritization
General prioritization - Prioritize test cases that will be beneficial on
subsequent versions
Version-specific prioritization - Prioritize test cases with respect to a
particular version of the software.
Hybrid :-
Under this technique is a Hybrid Approach of both Regression Test Selection
and Test Case Prioritization. Algorithms for the approach that have been
proposed are test selection algorithm and hybrid technique proposed

9. Pros And Cons
Challenges for regression testing :-
 With successive regression runs, test suites become fairly
large. Due to time and budget limits, the entire regression
test suite cannot be executed.
 Minimizing test suite while achieving maximum test
coverage remain a challenge.
 Determination of frequency of regression tests.

10. To ensure effective regression test, observe the
following:-
 Code being regression tested should be under a
configuration management tools.
The database used for regression testing must be isolated.
No database changes must be allowed.
No changes must be allowed to code, during the
regression test phase, regression test code must be kept
immune to developer changes

11. Tools used for regression testing
Relational
Functional
Tester(RFT)
selenium
Quick Test
Professional
(QTP)