Smoke Testing vs Regression Testing: A Detailed Evaluation

In software testing, two commonly known testing methods, Smoke testing & regression testing, share similarities but they are distinct pillars. Software testers employ diverse testing techniques, strategically deploying them at various levels to ascertain that the software is functioning as the intended purpose.

If you are looking forward to knowing about smoke testing and regression testing, what they are. Moreover, how they are set apart from one another, we will shed light on how they can be used to maximize the quality. So, let us start with their definitions and comprehensively explore smoke testing vs regression testing.

What is Smoke Testing?

Smoke testing is the preliminary level of testing conducted by the developers or testers to identify potential issues before it is used. It is an integral part of the Software Development Life Cycle playing a vital role in undertaking and achieving comprehensive software testing.

The testing doesn’t commence directly; instead, it necessitates a systematic approach when the software is ready. How do we know if the software is prepared for testing or not? Here comes the smoke testing in the picture; as discussed earlier, the principal objective of smoke testing is to scrutinize the core functionalities or features. The center focus of this testing is to determine if they (features & functionalities) are working as predetermined expectations or not.

If the intricacies of smoke testing are leaving you in a dilemma, assigning a software testing and QA company for this critical phase can be an ideal solution. Their expertise is tailored to deliver the best testing services and surpass optimal performance, ensuring the peak functioning of the software.

BONUS READ: A Quick Guide to Smoke Testing

Smoke Testing example

Let us assume smoke testing for a web-based project management application; during this critical phase, a series of checks are performed meticulously to ensure the reliability of the software. These essential aspects include the following:-

1) Login and authentication
2) Dashboard display
3) Create a project
4) Add a task to the project
5) Task assignment
6) Update task status
7) File attachment
8) Basic reporting
9) Logout
10) Cross-browser testing

Performing all of the above checks during the smoke testing can ensure the reliability and functionality of the software.

When should smoke testing be done?

Smoke testing occurs when a new software version is developed or merges with existing builds. It is paramount to ensure the seamless operation of all the features. This meticulous assessment is carried out by leveraging the black box testing approach. Smoke testing can be performed manually or automatically, but both methods aim to achieve the same purpose. However, it is necessary to swiftly ascertain the software’s proper functionality followed by the expectations.

What is Regression Testing?

Regression testing is not the same as smoke testing. It is a distinct phase of testing followed by the new build software. Regression testing focuses on the comprehensive examination and testing of the software and ensures that the recent code modifications have not adversely impacted the existing features.

It performs an in-depth verification to scrutinize the bug fixes or changes in the software environment, configuration changes, and a few others. The essence of this testing is to concentrate on scanning the software’s correctness while safeguarding the quality factor. It adopts the test-all approach to conduct changes in the software and ensures the existing functionality is not altered.

Regression testing is imperative as it is best practice to ensure high performance and remove uncertainties. By applying regression testing, developers can mitigate unforeseen difficulties, reduce the termination of software’s success, and provide customer delight.

Regression Testing example

Let us consider an example of Regression Testing for a mobile banking application:-

If in the mobile banking application, consider a scenario where a bug has invaded a problem with the fund transfer feature. It potentially causes problems for the users while transferring funds between accounts. To address such issues, the development team must diligently focus on rectifying the fund transfer module. In this context, let us check the series of checkpoints in the regression testing:-

Regression testing will begin from:-

1. Login to the mobile banking app
2. Navigation to the fund transfer section
3. Initiating transfer of funds between internal accounts
4. Do external fund transfer
5. Checks for transaction history
6. Testing the transaction limits
7. Confirming the fund functionality across multiple devices
8. Simulate network interruptions
9. Check for the security measures
10. Check that the notification system is functioning as expected

Performing this meticulous testing process safeguards unforeseen consequences and assures that the mobile banking application is secure, reliable, and functional even after resolving the bug in the fund transfer feature.

BONUS READ: Regression Testing – A Complete Guide

When should regression testing be done?

Regression testing is a crucial test conducted, followed by the successful modifications of smoke testing. It is often implemented for weekly releases after functional testing modifications are addressed. Below are a few key scenarios wherein regression testing is technically practiced:-

• Regression testing becomes paramount when the code modifications are done as per the requirements. This confirms that the changes haven’t impacted adversely, disrupting any of the existing features.
• When a new feature is slated to be included in the software, it verifies that introduced features keep the established software intact.
• When a particular bug fix is incorporated into the build, it ensures that bug remediation doesn’t invite unforeseen challenges in the existing software codebase.

Smoke Testing vs Regression Testing: Key Differences

We have summarized the generic process flow of both of these types of tests and how they differ from each other. It is important to note that the process flow may vary on a client basis.

Discussing the distinctions between smoke test vs regression test, can differ due to the scope and frequency they define. Understanding their key differences makes it easier to follow the best practices for both. Moreover, leveraging the capabilities of an automated testing platform can significantly elevate the entire development process.

Sr.No	Smoke Testing	Regression Testing
1.	Smoke testing is performed to check whether the newly built software is stable or not.	Regression testing is performed to verify whether the recent changes have influenced the existing functionalities or not.
2.	Both software testers and developers use it.	It is predominately used by software testers.
3.	The core reason for performing smoke testing is to confirm whether to accept or reject the newly built software.	Regression testing has nothing to do with the accountability of accepting or rejecting the software build.
4.	The cost of performing smoke testing is less.	The cost of performing regression testing can be high.
5.	Smoke testing requires less time and limited manpower compared to regression testing.	Regression testing is time-consuming and requires more manpower compared to smoke testing.
6.	Both automated tools and manual tools can perform smoke testing.	Regression testing can be performed by either automated tools or manual tools.
7.	Smoke testing is documented or scripted.	Regression testing is neither documented nor scripted.
8.	Smoke testing is performed right before the regression testing.	Regression testing on the other hand is performed during different phases of testing.
9.	Smoke testing is also known as “Build Verification Testing.”	Regression testing is not known by any other name.
10.	Smoke testing is performed at the beginning of the test phases or after the build is received.	Regression testing is performed after the code changes or modifications, mainly during the entire development life cycle.
11.	Smoke testing is not a detailed one. It is more of a quick check of the essential functionalities.	Regression testing is a detailed examination of specific functionalities impacted by the code changes.
12.	Example: To check if the login functionality is working proper or not.	Example: If the bug fixation caused any break in other features.

Smoke Testing vs Regression Testing: The Final Takeaway

Now, we are sure that you might have a clear understanding of regression testing vs smoke testing. Though there are a few stages of similarities and differences, each serves its own set of purposes and operates within its defined scope. Approaching a software development company that provides both smoke testing and regression testing services can help you understand your testing needs and time constraints. Finally, it’s paramount to acknowledge that both smoke testing and regression testing are critical to delivering quality software products.