Regression Testing: Definition, Techniques, and Importance

Regression testing is a quality assurance (QA) process that is conducted to ensure that a software application or system continues to function as intended after any changes or updates are made. 

It involves rerunning previously executed tests to verify that the changes have not introduced any new errors or bugs into the system. 

It is an essential component of the software development lifecycle (SDLC) and plays a critical role in ensuring the quality and reliability of software applications.

Techniques Of Regression Testing

There are several techniques that can be used for this type of testing. 

Some of the most common include:

1. Selective Testing

This technique involves running only a subset of the previously executed tests that are likely to be affected by the changes or updates.

2. Full Testing

This technique involves running all previously executed tests to ensure that the entire system is still functioning as intended.

3. Unit Testing

This technique involves testing individual units or modules of the system to verify that changes or updates have not introduced any new errors.

4. End-To-End Testing

This technique involves testing the entire system from end to end to ensure that all components are working together as intended.

Types Of Regression Testing

There are several types of regression testing that can be performed depending on the nature of the changes or updates that have been made. 

Some of the most common types include:

1. Functional Testing

This type of testing is conducted to ensure that the software application or system still functions as intended after any changes or updates are made.

2. Non-Functional Testing

This type of testing is conducted to ensure that the performance, security, and usability of the software application or system are still up to par after any changes or updates are made.

3. Backward Compatibility Testing

This type of testing is conducted to ensure that the software application or system is still compatible with older versions of the software or hardware.

Importance Of Regression Testing

Regression testing is an essential component of the software development lifecycle (SDLC) for several reasons. 

• Firstly, it helps to ensure that changes or updates made to the software application or system do not introduce new errors or bugs into the system. 

• Secondly, it helps to maintain the quality and reliability of the software application or system, which is critical for user satisfaction and retention. 

• Lastly, it helps to reduce the overall cost of software development by identifying and fixing issues early in the development process, before they become more expensive and time-consuming to fix.

Regression Testing Example

A regression testing example can help to illustrate the importance of this process. 

Suppose a software application is updated to include a new feature that allows users to upload files to the system. 

After the update, the software application is tested using selective testing to ensure that the new feature does not introduce any new errors or bugs into the system. 

If any issues are identified, they can be quickly fixed before the software application is released to the public. 

By conducting regression tests in QA, software developers can ensure that the software application or system remains reliable and functional, even after updates or changes are made.

Final Thoughts

Regression testing is a critical component of the software development lifecycle (SDLC) that ensures the quality and reliability of software applications and systems. 

By using various techniques and types of testing, software developers can identify and fix issues early in the development process, saving time and reducing costs. 

It is an essential process for software development teams that are committed to delivering high-quality software applications and systems.