What is Smoke Testing? – A Detailed Guide

Origin of Smoke Testing

The term smoke testing has its roots in hardware testing, specifically in the electronics and hardware manufacturing field. Engineers conduct smoke testing to check for basic functionality. Their primary purpose is to identify fundamental flaws or issues that could lead to a component or device literally emitting smoke due to a major malfunction.

The concept was later adopted in software testing, where a smoke test is a preliminary, basic set of tests conducted on a software build. The aim is to determine if the system is stable for further comprehensive testing. Similar to hardware testing, the software testing field aims to catch major issues early on, akin to identifying problems before they cause the “smoke” that indicates a significant failure.

It is a type of testing that helps uncover defects early in the development process.

What is Smoke Testing?

“What is smoke test” is a widely asked question when it comes to software testing. A smoke test is a type of software test that verifies that the most important functions of a program work. It is also known as “Build Verification Testing” or “Build Acceptance Testing”. The goal of this testing is to determine if a build is stable enough to proceed with further testing. Smoke tests are typically a subset of the full product test suite and involve basic functionality tests. It is often used as the first step of a larger testing process, as it helps to identify issues quickly before more time is spent diagnosing and repairing problems. 

In this article, we are going to know “what is smoke test” and how it’s used in the IT industry. Let’s get started.

When to Use Smoke Testing?

Smoke Testing is typically done at the start of a development cycle, after a build has been deployed to a test environment, to verify that the basic functions of the application are working correctly.

Let’s look at some scenarios with smoke testing examples– here

1. New Feature or Functionality Release

A popular smoke test example is testing a product when releasing a new feature. Releasing new features or functionalities is a frequent behavior for most software products.  As the releases are frequent, the testing team might not get a long duration to complete a test round.

During this scenario, the testing team can maintain an automated or manual smoke test suite to verify the stability of the product in each milestone release.  Once a new feature or functionality is added to the product, a defined software smoke test suite can be executed to check whether the addition of the new feature has caused any issues. 

2. Major Bug Fix or Update

After a major bug fix or update, this testing can be used to verify that the product is still in a stable state. 

A smoke test on a major bug fix would involve testing the fix to ensure it successfully resolves the bug. This could include retesting the functionality of the software, running the code through an automated testing suite, and examining the code to ensure it is free of any errors. Additionally, the test should include ensuring the bug fix does not introduce new bugs or have unintended side effects.

3. System Upgrade

After a software upgrade or patch, testing should ensure that the new smoke test software is compatible with the existing product.

For a system update, a smoke test would involve running basic tests that interact with the new system and checking for any unexpected errors or crashes. This would include running common scenarios, such as logging into the system, navigating through the smoke test software, and running basic queries. If any unexpected errors or crashes occur during the smoke test, the system update should be further investigated before being deployed.

4. Major Code Refactoring

Another popular smoke test example is testing the product after major code refactoring. After a code refactoring or major change in the code base, this testing can be used to ensure that the code is still functioning as expected.

5. Complex Branch Merge

After merging branches or merging multiple code changes, this testing can be used to ensure that all the changes have been successfully merged and the product is still in a working state.

A software smoke test after a branch merge would involve running a set of tests to ensure that the merge did not introduce any new bugs or regressions into the codebase. This could include checking that the code compiles correctly, that the unit tests pass, and that the application still functions as expected.

Who will Do Smoke Testing?

Upon deployment of a software build to the Quality Assurance (QA) environment, the QA engineers or leads engage in this Testing to verify the proper functioning of the application’s major features. This process is repeated for each new build release. The QA team checks for any showstopper issues that could affect the application under test. 

The Purpose and Importance of Smoke Testing

The main purpose of this testing is to identify major issues and quickly determine the overall stability of the application.

It helps to identify major issues and defects early in the development process so that they can be easily fixed before proceeding with more comprehensive and detailed testing.

It is also an important part of regression testing, as it helps to identify newly introduced issues on existing features that may have been caused by recent changes in the application code.

Goal of Smoke Testing: 

The primary objective of this testing is to determine whether the build is stable enough to proceed with further testing. This testing is crucial as it enables the early detection of major issues in the development process and saves significant time and resources.

Smoke Testing Example

Let us see an example to illustrate this testing.

Consider that a software company has developed a social media application. The development team completes the initial build of the application and decides to conduct a Smoke test to ensure that the software is running as expected.

In this scenario, the development team will run a few critical test cases on the application to ensure the software is stable by selecting them. During the Smoke test, the developers will check

• whether the application launches correctly,
• the home page and the login page load
• A user can log in

If the Smoke test passes, the development team can conduct more testing on the software. If the Smoke test fails, the initial build must fix the reported bugs before proceeding with other testing activities.

What is the Smoke Testing Cycle?

The Quality Assurance (QA) team starts the smoke testing phase when the development team finishes making a new software version. They do this by running a quick test to see if there are any significant problems with the software. They have a list of essential things to check and run many tests to ensure everything works.

If they find any big problems during the smoke test, they return the software to the development team to fix it. Then, the QA team runs another round of tests to make sure the fixed software works well with the other parts of the software. Once they finish these tests and everything looks good, they can move on to more detailed testing.

The main goal of the smoke testing phase is to find any major problems with the software before doing more detailed testing. That’s why they do it right at the beginning of the testing process.

Characteristics of Smoke Testing

1. Executed quickly

Testing is designed to be quick and easy to run. It should take only a few minutes or hours to run, depending on the size of the application. The quick nature of smoke tests ensures that any major issues can be identified and resolved quickly, helping to save time and money. 

2. Non-exhaustive

Smoke tests are non-exhaustive as they are designed to quickly determine whether a product is stable enough to be tested further. It does not cover every feature of the testing software. It is designed to be a high-level test of the most important functionalities. They provide a way to identify major problems so that developers and testers can focus their efforts on the most important issues.

3. Need to be Automated

Smoke testing should be automated using testing software so that it can be run quickly and easily. Automated tests can be run more frequently, as needed. Automation also ensures that the tests are consistently executed and reported in a timely manner, which allows developers to focus on more important tasks. Automated smoke tests also allow for easier regression testing, and can easily be incorporated into Continuous Integration (CI) pipelines.

4. Non-intrusive approach

The non-intrusive nature of testing offers many benefits. It allows testers to quickly identify major issues without having to dive deep into the code. This makes it easier and faster to identify any major issues in the system. Additionally, non-intrusive testing helps to reduce the cost of testing by having less time spent on debugging and fixing errors. 

5. Tests need to focus on Critical Paths

Software smoke testing should be focused on the critical path of the application, the most important features that need to work correctly. This can help reduce the risk of the project or process failure due to a system error.

What Happens if we don’t do Smoke Testing?

It is highly recommended to conduct this testing during the early stages of a project. Failure to do so may result in the discovery of defects during later stages, which can be both costly and potentially impede the release of deliverables. Timely testing can help identify and address issues early on, thus minimizing the risk of show stoppers and ensuring a smoother project outcome.

Benefits of Smoke Testing

This testing provides multiple benefits for the software development life cycle due to its nature of execution. Let’s look at some of the major benefits gained through smoke tests software.

1. Helps to identify major issues quickly – This testing can identify major issues in an application quickly and efficiently saving time and resources that would be wasted if deeper tests were performed on an application.
2. Helps to ensure quality – This testing helps to ensure quality by identifying the most critical functions of a software application and verifying that they are working correctly.
3. Helps to identify problems early in the development cycle – This testing is usually performed early in the development cycle. This helps to identify problems early in the process, which means they can be fixed before they cause major issues later on.
4. Helps to ensure compatibility – This test can be used to ensure that the application is compatible with its intended and multiple environments. This ensures that the application will work correctly when it is released.
5. Helps to reduce cost – Because the scope of this testing is limited to the most basic functionality, it is efficient and cost-effective.
6. Provides Increased Confidence – This testing can give developers and testers more confidence in the quality of the application. This can help to reduce stress and increase morale.
7. Facilitates Increased speed of deployment – This testing can quickly identify functional issues that may impede the successful and quick deployment of a product.

Limitations of Smoke Testing

Let’s look at some major limitations QA Engineers and Developers face with this testing

1. It is not a substitute for other types of testing – Smoke tests are usually a small subset of tests that are run whenever a new build of an application is ready. It only tests the most important functionalities. Therefore it is not good to consider a smoke test as a substitute for other testing types such as integration, system, or acceptance testing.
2. Limited in scope and depth – The major drawback of smoke tests being limited in scope is they may fail to cover all areas of the system, Due to this some bugs may remain undetected.
3. It will not detect performance issues – Smoke tests do not provide any meaningful metrics or data to analyze the performance of the system such as response time or scalability, that can only be detected by running comprehensive tests.

Sample Smoke Test Cases Example

ID	Test Scenario	Description	Steps	Expected result
101	Verify that Login Functionality is working	A user with valid credentials should be able to login on providing valid credentials.	1. Launch the application 2. Navigate to the login page 3. Enter a valid username 4. Enter a valid password 5. Click on the login button	User should be able to login successfully
102	Navigation Menu should be working	Check if all menu options are accessible and functioning properly.	1. Open the application and log in. 2. Click on each menu option individually (e.g., Home, Profile, Settings). 3. Observe if each page loads correctly without any errors or delays.	Each menu option should open its respective page without any issues or errors.

How does Smoke Testing Work?

This testing typically involves running a set of basic tests on a software application to ensure that it can perform its most important functions. These basic tests might include testing the application’s user interface, basic navigation, and data entry and retrieval. If the application passes these tests, it is considered “smoke tested” and is ready for more detailed testing.

4 Steps of Smoke Testing Process

When it comes to ensuring the stability and viability of a software build, the smoke testing process stands as a pivotal gatekeeper. This concise yet crucial phase involves a strategic sequence of steps that swiftly assess whether a software build is fit for further testing or requires immediate attention.

Prepare for the Tests

Before diving into smoke testing, thorough preparation is crucial for an effective and efficient process. This step involves defining the scope and objectives, selecting high-priority test cases, and ensuring the testing environment is properly configured.

Create the Smoke Tests

With a well-defined plan in place, proceed to create the smoke tests. This step involves developing concise and targeted test cases, prioritizing them based on criticality, and documenting the necessary test data for execution. Since it is smoke testing, make sure to create tests that are necessary to verify the core features.

Perform the Tests

Next up, you have to execute the test cases created in the previous step. Run the selected test cases, analyze the results, and determine the overall status of the software build to decide if it is suitable for high-level assessment.

Report and Repeat

The final step involves reporting the findings and iterating the process as needed. The pass/fail status of the smoke tests determines the future testing scenarios.

Tips for Performing Smoke Tests

Despite following the correct steps to run smoke tests efficiently, the chances are you can encounter problems. These tips can save you time and effort in such cases:

• Design simple and straightforward test cases that focus on the core functionalities.
• Clearly define the testing criteria to avoid over-testing.
• Assign smoke tests to the QA engineers who carry some experience.
• Consider automation testing for cases that are repetitive.
• Conduct regular reviews of the smoke test suite to ensure it aligns with the current software requirements.
• Place high emphasis on collaboaryion between QAs and developers to effectively run smoke tests.
• If applicable, execute smoke tests in parallel to save time.
• Perform testing for every new build.

Types of Smoke Testing

This testing can be categorized as Formal and Informal Testing. 

1. Formal

In this method, the development team delivers the application to the Test Lead. Then the test lead will instruct the QA team to conduct this testing. Once the testing team concludes the testing, they will send the testing report to the test lead.

Read all about Formal Testing.

2. Informal

Here, the Test lead informs that the application is ready for testing. The test leads do not instruct the QA team to carry out this testing, but still, the QA team starts testing the application by conducting a testing round.

Different Ways to Perform Smoke Testing

1. Manual Testing

Manual smoke testing involves running a series of basic tests manually to ensure that the software behaves as expected. It typically involves testing the most basic functions of the software such as logging in, creating a new account, viewing a list of data, and performing basic searches. If any of these tests fail, the software is considered to be in an unstable state and further testing should not be conducted until the issue is fixed.

Read a detailed guide on Manual Testing

2. Automation Testing

In automation testing, you use testing software to automate the test execution. Automated smoke test suites are used to verify that an application is functioning correctly before more in-depth testing is performed. Automated smoke tests can be used to identify any major issues that need to be addressed before more thorough testing is performed.

Read a detailed guide on Automated Testing

3. Hybrid Testing

This is a combination of both manual and automated testing, where manual tests are used to supplement automated tests. It combines the benefits of manual testing, such as the ability to test complex scenarios, with the benefits of automated testing, such as faster test execution and the ability to run tests repeatedly. Hybrid testing is used to improve test coverage and is especially useful for ensuring that complex user flows are tested accurately and consistently. 

Smoke Testing Failure Categories

As the elementary part of software testing, this testing covers a broad range of activities. It can be checking the filters of a search bar or validating if the menu drop-down is working. In all of this, it is easy to overlook the simple requirements. The test can fail, and these are all the reasons why.

• The smoke test is only to verify the basic functionality. If that fails, further testing is halted. But if QAs go deeper into feature analysis in the name of this testing, it is always bound to fail.
• This test is supposed to save you time and resources. Any issue in the basic function means going back to square one. Failure to do so is a huge red flag and just the opposite of what the smoke test intends to do.
• Huge negligence would be not defining what a smoke test is for a particular project. If your team does not know the features that come under this testing, they will not know when to mark it as failed.

What is a Successful Smoke Test?

A smoke test’s purpose is to uncover fundamental defects in the system before it goes for further testing and save you time. In that case, a successful smoke test should match the basic functional requirements. Another aspect to be mindful of is that this testing is not designed to catch all bugs; it does not have to be thorough. So, the right way to make your testing successful is to focus on checking the core functions only.

Tools for Automating Smoke Testing

Some of the major tools that automate smoke testing are:

1. Testsigma: Testsigma is an ideal tool for automating your smoke tests because:

i.You can start automating your tests in minutes with Testsigma. ii. It lets you author automated tests, like writing test cases in simple English. It’s a no-code test automation tool; thus, to begin with test automation, you don’t need to be a coding expert. iii. The automated tests are as easy to edit as they are to create.

iv. It is a complete eco-system where you can author your tests, execute them and get the reports for them simultaneously. Thus, you get all your test automation needs in one place.

v. It lets you automate your web, mobile, APIs, and desktop tests from the same place. Thus, you don’t have to set up different tools for automating different platforms. vi. It is built with highly customizable reporting features. Thus, you can adjust the reporting according to your needs. vii. Testsigma is also available as an open-source and free version. Start automating your smoke tests with Testsigma Open Source.

Know more about Testsigma

2. Selenium: Selenium is an open-source test automation tool that automates the test cases to test a website’s behavior on a browser. It can only automate test cases for a web application on a browser and is not usable for automating test cases for desktop or mobile applications.

Get the detailed comparison of Selenium vs Testsigma

3. TestComplete: TestComplete is an automated UI testing tool developed by SmartBear Software. It helps create, execute, and maintain smoke tests across mobile, web, and desktop-based apps. TestComplete allows you to develop test cases in various languages such as Java, Python, etc. It can record the key actions needed to replay the test.

4. QTP/UFT: This is another commercial automation tool. It is similar to TestComplete in that it can automate smoke testing. It supports test automation for APIs, mobile, desktop, and web apps. It also includes additional features such as object recognition and data-driven testing.

5. Ranorex: Ranorex helps you create and execute smoke tests for web and mobile applications. This tool allows the user to record test steps as actions on the application under test and then play it back later. The recorded steps can also be modified and fine-tuned.

Know the detailed comparison of Ranorex vs Selenium

How to Perform Smoke Testing on Testsigma?

You can use Testsigma as a smoke tests software to simplify the smoke testing process. It allows users to create automated test scripts and execute them against their application. Testsigma also provides an in-depth analysis of the results and allows users to debug any errors. With Testsigma, organizations can carry out quick smoke test rounds to detect any issues in their applications and fix them.

Real Time Website and Web App Testing

Testsigma is a modern, cloud based test automation platform that enables users to quickly and easily create automated tests for real-time testing of websites and web applications.

Web Automation and App Testing

Testsigma can be used to test web applications on different platforms and browsers.

Real Time Mobile App Testing

Testsigma is used for real-time mobile application testing using its easy-to-use and intuitive interface. It is compatible with both Android and iOS platforms and supports a wide range of mobile application types, including native and hybrid applications.

Best Practices for Smoke Testing

1. Analyze the software requirements thoroughly to understand the expected behavior.
2. Develop a comprehensive test plan that outlines the tests that should be performed and the expected results. It helps to ensure that testing is conducted efficiently, as it provides a clear understanding of what tasks must be completed, by whom, and when.
3. Design simple and straightforward test cases.
4. Identify and prioritize the most important test cases. You should only choose test cases that cover the most critical areas of the system.
5. Fast execution of the tests. This testing should only take a few hours to complete.
6. Document the test results as test reports. Test reports are necessary to provide relevant parties with an overview of the quality of a product or service.
7. Conduct a triage and review the results.
8. Repeat the process for each subsequent release of the system.

Summary

In this article, you learned about what is smoke test. When to use this testing? Examples with the real world, The Importance of this testing, Characteristics, Benefits, Limitations, Types, and Best Practices. Further, we discussed the difference between sanity testing and smoke testing.

Frequently Asked Questions

Why is it called smoke testing?

The term “smoke testing” originated in the hardware industry, where it was used to refer to a type of test in which a device was powered on and checked for any visible signs of smoke or fire. The analogy was later applied to software testing, where a smoke test is used to check a software build for basic functionality and identify any major issues that need to be addressed.

Who performs smoke testing?

It is typically performed by software testers or quality assurance personnel. Developers too can use this testing to verify that the code they have written is functioning as expected.

Is smoke testing manual or automation?

It can be either manual or automated. Also, it can take the nature of a hybrid too. Hybrid typically refers to a combination of manual and automated testing techniques. 

Is smoke testing black box?

It can be done by a person who has internal code knowledge such as a developer. In that case, the developer can be categorized as a white box tester. Also, this testing can be done by a person who doesn’t have internal code knowledge such as Quality Assurance Engineer. At that time tester will be considered a black box tester. Usually, this testing falls under black box testing but there can be situations where it can become white box too.