Skip to main content

Regression testing Introduction

Regression testing is any type of software testing which seeks to uncover regression bugs. Regression bugs occur whenever software functionality that previously worked as desired, stops working or no longer works in the same way that was previously planned. Typically regression bugs occur as an unintended consequence of program changes.

Common methods of regression testing include re-running previously run tests and checking whether previously fixed faults have re-emerged.

Types of Regression

Local - changes introduce new bugs.
  • Unmasked - changes unmask previously existing bugs.
  • Remote - Changing one part breaks another part of the program. For example, Module A writes to a database. Module B reads from the database. If changes to what Module A writes to the database break Module B, it is remote regression.

There's another way to classify regression.

  • New feature regression - changes to code that is new to release 1.1 break other code that is new to release 1.1.
  • Existing feature regression - changes to code that is new to release 1.1 break code that existed in release 1.0.

Uses of Regression Testing

Regression testing can be used not only for testing the correctness of a program, but it is also often used to track the quality of its output. For instance in the design of a compiler, regression testing should track the code size, simulation time and compilation time of the test suite cases.

Recommended Resources
Testing Interview Questions -
Testing Tools Interview Questions -
What is Software Testing?-
Software QA & Testing Resource Center-
Testing Faqs-


do check the for ur desired regression tools
Anonymous said…

מלון [url=]כפר בעיר[/url] - שלווה, [url=]חדרים[/url] מרווחים, אינטימיות, [url=]שקט[/url] . אנחנו מציעים שירותי אירוח מיוחדים גם ישנו במקום שירות חדרים הכולל [url=]סעודות רומנטיות[/url] במחירים מפתיעים אשר מוגשות ישירות לחדרכם!

לפרטים נוספים נא לפנות לאתרנו - [url=]כפר בעיר[/url] [url=][img][/img][/url]
Anonymous said…

Developers need to stay ahead of their competitors and get their product on the market in a timely manner. Mansour Engineering understands that time is money. Mansour Engineering will meet your goals, schedule and budgets while maintaining creative integrated development economics.

[url=] click here to go to Mansour Engineering[/url]
Anonymous said…
Hello. My wife and I bought our house about 6 months ago. It was a foreclosure and we were able to get a great deal on it. We also took advantage of the 8K tax credit so that definitely helped. We did an extensive remodeling job and now I want to refinance to cut the term to a 20 or 15 year loan. Does anyone know any good sites for mortgage information? Thanks!

Software testing type which seeks to uncover regression bugs, and software functionality that previously worked as desired i understood this logic, so thanks allot for shearing this article.
Anonymous said…

[url= ] Compared Translations of the meaning of the Quran [/url]

"Can a Muslim have more than one wife?"

The religion of Islam was revealed for all societies and all times and so accommodates widely differing social requirements. Circumstances may warrant the taking of another wife but the right is granted, according to the Quran, only on condition that the husband is scrupulously fair.

For more details [url= ]click her[/url]


All of us will die one day INCLUDING YOU.

so before you die you must find out where the HELL you are going too.

You must find out

who is our savior Jesus or ?

You may sleep tonight and never get up in the morning?

You may die today.

You may die within a week

You may die within a month

you may die within a year

you may die within the next ten years

one thing for sure

You will die

so find out how is our savior so that he may save you.
Win8 said…
I can't wait to read far more from you. This is actually a tremendous web site.
Win8 said…
I can't wait to read far more from you. This is actually a tremendous web site.

Popular posts from this blog

Istqb,cste inforamtions and training centers in India

About istqb:
The ISTQB was officially founded as an International Testing Qualifications Board in Edinburgh in November 2002 and it is responsible for the "ISTQB Certified Tester", which is an international qualification scheme.

ISTQB is the parent body responsible for approving various national boards in addition to other tasks such as defining the syllabi for various certifications.
website url: FAQ :

for examination and preparation and sample question papers available in below link

will be helpful for ISTQB

join yahoo groups:
in this group you can ask your queries about istqb examinations and certification related doubts and sample papers to certified level and advance level question keep on raised by members.

ISTQB-India@ yahoogroups. com

CSTE information:

QAI, India, the premier knowledge corporation in the software engineerin…

Equivalence partitioning

Equivalence partitioning:
Equivalence partitioning is a method for deriving test cases. In this method, classes of input conditions called equivalence classes are identified such that each member of the class causes the same kind of processing and output to occur.

In this method, the tester identifies various equivalence classes for partitioning. A class is a set of input conditions that are is likely to be handled the same way by the system. If the system were to handle one case in the class erroneously, it would handle all cases erroneously.

Equivalence partitioning drastically cuts down the number of test cases required to test a system reasonably. It is an attempt to get a good 'hit rate', to find the most errors with the smallest number of test cases.

To use equivalence partitioning, you will need to perform four steps:
Determining conditions to be TestedDefining TestsDesigning test casesIdentifying Final set of Test Cases

Defining Tests

A number of items must be considered when…

Cyclomatic complexity

Cyclomatic complexity is a software metric (measurement). It was developed by Thomas McCabe and is used to measure the complexity of a program. It directly measures the number of linearly independent paths through a program's source code. It is computed using a graph that describes the control flow of the program. The nodes of the graph correspond to the commands of a program. A directed edge connects two nodes if the second command might be executed immediately after the first command.


M = E − N + 2P


M = cyclomatic complexity
E = the number of edges of the graph
N = the number of nodes of the graph
P = the number of connected components.

"M" is alternatively defined to be one larger than the number of decision points (if/case-statements, while-statements, etc) in a module (function, procedure, chart node, etc.), or more generally a system.

Separate subroutines are treated as being independent, disconnected components of the program's control flow graph.