Regression Testing, and the various factors that affect it.  

Regression Testing, and the various factors that affect it.  

Testing is a very elaborate and tricky process, as it requires everything to be in unison, working together so perfectly, that it meets with the standards set for it. A lot of perfectly planned and synchronised steps are required to make sure that a certain software is working as per our expectations, and one of those steps is Regression Testing, which is a very important and highly necessary step.  

What is regression testing?  

Regression testing is software testing type that which is done to make sure that any code change done to the software doesn’t impact the existing code and sequence, or the existing functionality of the product.  

Every software goes through a lot of code changes, bug fixes or other changes, to make sure that it works according to the required parameters. As such, a lot of changes are required to be done throughout the entire process. These changes could be done by anyone from anywhere, and while they can be easily tracked and are updated in real time, it also needs to be made sure that these changes do not negatively impact the already existing flow of the software, which is why Regression testing is done.

It is important to make sure that you done regression testing in software, as it makes sure that your entire product functions properly. Most of the time, regression testing is an automated process, which doesn’t require much manual input. 

When to perform Regression testing? 

Regression testing must and should be applied for every software that is under development. Of course, the circumstances could vary every single time. Here are some of the circumstances that might need regression testing: 

  1. When a new piece of code is added to an existing body of code  
  2. When a new feature or functionality is added 
  3. When defects are solved with the help of codebase 
  4. When performance is improved by optimising the source code 
  5. Patch fixes are added 
  6. When there are changes in the configuration 

Why is regression testing important?  

One would think that functional testing is enough to make sure whether or not a software is working properly, but it is important to note that functional tests only inspect the behaviours of the new features and capabilities, but do not check how compatible they are with the existing ones.   

This is why Regression Testing is highly important.  

Employing Regression testing early on in your deployment cycle will help save a lot of time, money and efforts, as it will not only check whether or not your code is functioning properly, but will also check for any bugs, and even check whether every piece of code is functioning the way it is supposed, with the others, and give you a heads up if it doesn’t.  

Simply put, no matter how many changes are done to your product, and how frequently they are done, regression testing ensures that the quality of the product is not lost.  

How to do Regression Testing  

The way regression test is done varies from organisation to organisation, and steps employed in the test also vary accordingly. However, there are a few basic steps, which anyone would have to stick to, while performing the test. They are: 

  1. Detecting the changes in the source code 
    Detecting every small change, modification or optimisation in the source code is the first step towards regression testing. Understand what was changed, and how they impact that which already exists.  
  2. Prioritising these changes 
    These changes that were made need to be prioritised first, before anything else, and need to be put ahead of the rest, for testing.  
  3. Determine the entry point and the entry criterion 
    Before executing the regression test, make sure that your application meets with the pre-set eligibility criterion.  
  4. Determine exit point 
    Determine what the exit point should be, or the minimum conditions, set up earlier.  
  5. Schedule tests 
    After everything is set and done, you can begin by scheduling the tests and performing them.  

Selecting test cases for regression testing  

Most of the defects reported by customers arise from last minute bug fixes, which cause side effects. This is the best-case example to demonstrate that selecting a test case for regression testing is not that easy, and needs to be done carefully. A number of cases can be considered for regression testing, based on what they are. Here are a few cases where regression testing can be employed: 

  1. Test cases that show frequent defects 
  2. Features of an application which are more visible to the users, and the most used 
  3. Test cases which verify the core features of a product 
  4. Test cases of functionalities that have undergone more and recent changes 
  5. All integration and complex test Cases 
  6. Boundary value test cases 
  7. Sample of successful and failure test cases 
  8. Modules where recent code changes were done. 

Regression Testing Tools

A number of regression testing tools are used by various firms, but here are a few popular tools that are used for regression testing: 

  1. Katalon 
    Katalon Studio is an end-to-end automation testing solution which supports both functional and regression testing, making these processes as simple as they can get, for those performing the test. 
  2. Selenium
    Selenium remains to be one of the top tools for browser-based and cross-platform based regression testing. It also supports automated test scripts that cycle through data sets and data-driven tests. Selenium is also the most suitable for large-scale quality assurance teams with advanced testers. 
  3. IBM Rational 
    Rational Functional Tester, or RFT, is a tool for software test automation from IBM, hence known as IBM RFT. It can be used for a wide range of software testing types, including functional, regression, GUI, and data-driven testing, applications (web-based, .Net, Java, Siebel, SAP), and more. 
  4. Apache JMeter 
    It is an open-source test automation software used to load functional test behaviours and measure test performance. 
  5. Avo Assure 
    Avo Assure is a no-code test automation solution which helps you test end-to-end business processes with a few clicks of the buttons. This makes regression testing more straightforward and faster. 

Regression testing challenges  

  1. With successive regression runs, test suites become fairly large.  Due to time and budget constraints, the entire regression test suite cannot be executed 
  2. Minimizing the test suite while achieving maximum Test coverage remains a challenge
  3. Determination of frequency of Regression Tests, i.e., after every modification or every build update or after a bunch of bug fixes, is a challenge.

Types of regression testing  

  1. Unit
    Unit Regression is done during the unit testing phase, and the code is tested in isolation. The unit to be tested is isolated so that the unit can be tested individually without any discrepancy, and without this unit affecting any other parts of the code.
  2. Partial
    Partial Regression is done to verify if the code works fine, even when changes have been done in the code and the unit is integrated with the unchanged or already existing code. 
  3. Complete 
    Complete Regression testing is done when a change in the code is done on a number of modules and also if the change impact in any other module is uncertain, of the change already done. The product as a whole is regressed to check for any changes because of the entirely changed code. 

Regression Testing and Configuration Management  

The configuration for regression testing should always be done before performing regression testing. While this configuration depends upon the software that is being worked on, and the requitements, here are a few basic configuration requirements that everyone follows: 

  1. Outbound emails should be disabled 
  2. Database should be backed up 
  3. Every element of the code should be uniquely named 

Difference between Re-Testing and Regression Testing  

Re-testing literally means “testing again”, for whatever the reason may be, but usually, it means testing for something in particular. for a specific reason. Re-testing is done when bugs in the source code are fixed, or when the final test case fails and needs to be re-run, to identify what the problem may be.  

On the other hand, Regression testing is performed to check whether the changes or updates done to the code has caused any new defects in the existing functions. This type of testing ensures the unification of software. 

Moreover, automation is a highly crucial feature of regression testing, which allows you to make the most of the capabilities of your test case. Additionally, regression testing also eliminates any or all underlying side effects caused by code changes, in the most effective way possible.   

The future of regression testing

For any testing methodology to work effectively, it needs to be a part of a comprehensive testing design. The same is the case with Regression testing. While Regression testing is working at its best right now, it has a long way to go, as it would eliminate any errors in the final product in the most cost-effective way possible, if done right. As such, there are several ways in which Regression Testing can go forward in the future, but this method of testing is here to stay. 

Moreover, no matter what kind of testing strategy you may employ while software testing, it would never be complete without regression testing, as it saves a lot of time and energy, by testing your code for functionality and making sure that bugs are fixed or code is replaced within a short span. Hence, the chances of Regression testing getting more and more popular is more likely than the contrary.  


While there are several ways of testing your software for different kinds of errors and testing it for efficiency, Regression Testing is one of the most crucial parts of software testing, as it holds the entire product together. It makes the process of making sure that every piece of code is coherent and that everything works together perfectly, making the whole product the best in quality.  

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