What is Smoke Testing and why is it important?


A quality product is what makes a difference for enterprise businesses today for which effective software testing is essential. It plays an important role in achieving quality. There are different types of software testing methods such as unit testing, integration testing, system testing, smoke testing, sanity testing, functional testing, non-functional testing types, etc. Out of these, smoke testing is a testing method that has importance among these listed software testing methods.
Smoke testing has got its name from hardware repair systems wherein a smoke test is performed on pipelines to know whether they are working or not. This type of testing is also named build verification or build acceptance testing. Specifically, this should be the first method of software testing that needs to be executed when once any new code deployment or code update is done for software projects.

Smoke Testing – ‘Verifies build stability’


The QA team is primarily focused on the smoke testing process which is usually taken up in the QA environment when a new build is deployed. It tests whether all the test environment aspects are running successfully and if the build is stable or not and justifies if the build can be used for the further testing process. This testing method is designed to test the core functionality of a new build and if the smoke test fails then it is very likely the build is immediately rejected by the QA team. The outcome of this smoke testing is critical to determine whether a build is stable enough.

What is the scope of Smoke Testing?
Basically, smoke testing is a rapid regression test of the major functionality and shows that the product is ready for further testing. With the smoke testing method, most of the defects are identified at the initial stages of software development and helps in the correction of identified defects.

When is Smoke Testing performed?
This testing should take place at the beginning of the software testing life cycle. Smoke testing quickly verifies the quality of the build and evaluates the basic tasks whether they can be executed or not. This method of testing should be performed when there is a change in the build or every time a new build is deployed.
This type of testing checks the stability of the code for each sprint with a new code deployed. This testing method is executed before any detailed functional or regression testing is taken up as it requires very little time to get an overview of the new code stability.
In smoke testing, the test cases usually cover the most important functionalities of the system. The basic objective of this method of testing is not to perform exhaustive testing, but to verify that the critical functionalities of the system are working fine.

Benefits of Smoke Testing

  1. Detects and picks up the show stopper bugs early in the software life cycle and saves time
  2. Works as a gatekeeper to accept or reject a build based on its stability to allow for the further testing process
  3. Identifies critical blocker bugs at early stages and helps for faster bug resolution
  4. Enables quality improvement as major issues are detected and corrected much earlier in the software test life cycle and thereby increases the quality
  5. Helps uncover some of the obvious errors which save time and effort for the testing team
  6. Eases progress assessments for project managers as this method helps to assess the software development progress

Important tips for performing Smoke Tests

  1. Conduct smoke tests during the early stages of a project or product
  2. Regularly record all the smoke tests
  3. Smoke tests should not take more than an hour
  4. These tests should be conducted for every sprint and every release
  5. These tests are essential to be performed for each new build deployed
  6. Essential to maintain a test case repository
  7. Automate smoke tests wherever possible to reduce time and cost
  8. Conduct smoke tests for all important and critical functionalities across new builds

What are the steps involved in Smoke Testing and how to perform them?

Identify smoke test cases
This is a very important step while performing the smoke tests.  It is essential to identify the minimum number of test cases to cover the crucial functionalities of the product so that they can be executed quickly.

Create smoke tests
The identified smoke tests should be used to create test cases around them. The test cases are developed manually and test scripts can be created to perform automation.

Run smoke tests
Once the smoke tests are created then they can be run on the build and results can be analyzed.

Analyze smoke tests
After the smoke tests are performed the results should be analyzed to know whether the build is a pass or a failure.
Smoke testing can be performed either manually or in some cases, automation can also be adopted. Basically, there are three types of Smoke tests listed below:

Types of Smoke Tests
Manual smoke testing
Manual smoke testing is performed in order to find the critical functionalities and it helps uncover the high quality and critical bugs in the initial stages of software testing by quickly going through the application.

Automation smoke testing
It is a part of regression testing and here the testing team automates the test cases before the build is released to the testing team. Test cases can be automated using various automation frameworks available in the market. Automated test cases are helpful as they help in reducing the manual efforts of the testing team every time the new build is released. Once the test cases for the smoke tests are automated, QA teams run the job having the automated test suite providing speedy results without any manual intervention to find the stability of an application.

Hybrid smoke testing
This is a combination of both manual and automated testing methods which improves the overall smoke testing performance.

Major differences between Smoke and Sanity Testing


1. Smoke testing is mostly used to check critical functionalities of a software build while sanity testing focuses on minor areas or minor functionalities.
2. Smoke tests can be performed either manually or in some cases can also be automated. But, typically sanity testing does not have any specific test cases or test scripts.
3. Smoke testing is also called build verification testing and is a subset of acceptance testing while sanity testing is a subset of regression testing.
4. Majorly, this testing should be done for the entire application for each sprint when a new build is deployed while sanity testing is taken up to test only some critical components.

Advantages and Disadvantages
Advantages

  1. One of the biggest advantages of Smoke testing is that it helps in the early identification of the defects found in the critical functionalities of the system
  2. Smoke testing helps in reducing the risk of failure as the defects are found early
  3. Smoke testing is quite easy to perform as no special efforts of the testing team are required
  4. Smoke testing helps in saving the time and efforts of the testing team
  5. It helps in the overall improvement of the quality of software applications
  6. It needs only a limited number of test cases to be executed covering mostly positive scenarios

Disadvantages

  1. Proper documentation is required in case of Smoke testing so a specialized testing team is required for this purpose.
  2. Smoke testing sometimes causes the wastage of time if the software build is not stable.
  3. In case of some minor changes in the application, performing the smoke testing around the whole application from end to end is not viable.
  4. Sometimes even after smoke testing of the whole application, critical issues arise in integration and system testing.
  5. Any bug/ issue left in smoke testing can cause blunders in the future

Conclusion
There are different types of software testing which include unit testing, integration testing, system testing, sanity testing, smoke testing, interface testing, and many more. Among these testing methods, smoke testing plays an important role as it is performed on every new build to check if the build is broken or can be utilized to further testing.
Before releasing any software application, different types of testing are performed at different points. It is one of the most important types of testing and has a simple motive for finding defects in the early stages in order to verify that the most important features of the software are working fine.

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