Smoke Testing: A Comprehensive Guide to Early Defect Detection

Did you know the software development industry hit the 45 billion mark in 2024? With customers demanding smooth functioning and excellent app performance at all times, high-quality software is a necessity. While businesses have used the best manual and automated methods to ensure seamless performance, the key lies in mastering the basics. And what does that mean?

We are talking about smoke testing, which can help you find defects in the application at earlier stages and save the time of QA (Quality Assurance) teams. This is all the more essential, as fixing defects after release can be 30 times more costly than addressing issues after the implementation stage. There is much more to smoke testing; we will explore all the aspects in this blog.

Smoke testing is a software testing method in which the most critical and fundamental application features are tested to ensure smooth working. It is a preliminary health check, and “Smoke” comes from hardware testing.
Earlier engineers would power up a device if it didn’t emit smoke; it was said to have passed its first basic test. However, smoke testing cannot be considered one-and-done as it doesn’t deep-test all features.

You should use it only to ensure that core functionality is in place and no significant issues would prevent further testing. Testers or developers can perform these tests, and once they are performed, they are sent to the QA team for additional tests.

Here are some of the parameters that are checked during a smoke test.

• A responsive user interface is a customer’s basic demand. So, developers run a smoke test to ensure it works as expected and addresses bugs.
• It doesn’t matter if the site has been developed aesthetically or if essential functions like login features, screen navigations, and submission forms are not working perfectly. A smoke test rules out any issue with these aspects.
• The next check is to see if essential workflows are being efficiently executed. If users can search for products on your site, add them to their carts, and purchase them with zero hassle, then the smoke test is considered successful.

Now that you understand the basic parameters, you need to know the situations in which smoke testing is performed.

• Post-Launching New Application Versions (Build): After developers have fixed defects or added features, you should run a smoke test on the updated version to check for issues.
• Post Deployment: If the software is deployed on a test or production server, smoke testing is used to check that the deployment was a hit or a miss
• After Integration: If multiple teams have worked on the software, smoke testing will help confirm whether all pieces work together.

Here is how you can check some of the basic features of a build with scripts.

This is to check if an application can launch quickly with zero errors.

This test will help you check if users can log in with valid credentials.

This script lets you check if a form works in the desired manner if basic inputs are given.

This will help you check if a page loads correctly in minimal time.

This is to check if users can navigate your website with ease.

The primary purpose behind smoke testing is to ensure the application version is ideal for further testing. For any reason, if you decide to leave it for a later stage, you are setting yourself up for frequent app crashes and failures. Thus, it is always better to spare some time, do a smoke test, and ask developers to fix these issues. Even if the developers cannot resolve these issues, your team will save time not working on a defective application.

Let’s understand it with an example of a weather application.

Testers need to check if:

• The home screen loads correctly
• City searches can be performed
• The right temperature comes for the specific city

Even if a task fails, the app is not ready for detailed testing. However, if the smoke test was successful, you can verify whether the app’s speed is optimum and whether the notifications are working correctly.

While the purpose of smoke testing is straightforward, you can conduct a smoke test in multiple ways.

Manual testing is usually done for small projects with no automated scripts. Testers or developers do it, and human intelligence forms the basis of such tests. While flexible, it requires a lot of time, resources, and energy, and a tester needs to put dedicated effort into it.

Such tests use automated scripts or tools to conduct smoke tests and are ideal for Continuous Integration/Continuous Deployment (CI/CD) pipelines. The best thing about using these tools is that you can say goodbye to human errors, save time, and run these on multiple environments. However, these tests lack the human touch and don’t do justice to the experience required for application testing.

Hybrid testing is ideal for conducting smoke tests as it combines the best of both worlds. While some cycles of smoke testing are completed using automated scripts, others are checked by a tester. This leaves no room for error; if the build is deemed fit, it can be sent further for testing. This method not only helps you save time and costs, but it also guarantees the best results.

Further Reading

• Manual Testing vs Automation Testing: Your Complete Decision Guide
• Mastering Software Quality: A Guide to Software Testing Types

While smoke testing is cost-effective and quick, there are better options for deeper testing. It should only be considered an initial step to avoid efforts in the later stage. Let’s understand the different advantages and disadvantages of smoke testing.

Tell us something which you would choose:

• Solving issues one by one
• Dealing with a heap of problems that leave you frustrated.

We are sure you would choose the first option.

Similar is the case with smoke testing. There is no point in running in-depth tests on an application if it fails basic tests. Fixing errors at this stage will lead to unnecessary delays and extend the testing process. Smoke tests help developers fix the issues faster as they get quick feedback. This, in turn, ensures superior software quality.

Smoke testing is a no-brainer when it comes to boosting the quality of your software. Knowing that your designed application is robust and can satisfy customer needs, you can focus on other needs.

What if you could save time at later stages and be aware of issues earlier? Well, smoke testing helps you do that and much more. As you will be aware of the defects in the earlier stages, you can save time by not working on unstable builds. Since the bugs are identified beforehand, they will be easier to debug and only save you time.

Let’s be honest. Your developers and testers have multiple projects to handle. With smoke testing, only good-quality application versions are sent further. When you catch issues early, you can easily keep projects on track and pave the way for more predictable and consistent release timelines.

Reworks and frequent issues in application versions can lead to friction between teams. Smoke testing is a great way to clarify whether a build is ready for further testing. With smoke testing, teams can focus on problem-solving rather than fixing issues here and there.

Customers want applications that work seamlessly and are easier to navigate and use. Smoke tests help you ensure that all critical components and functions work and deliver only the best products to your customers. Moreover, this will also build trust with stakeholders and massively improve user experience, as a stable release leads to minimal production issues.

Have you ever thought about expediting software delivery through automated validation? Smoke testing has a significant role as it helps you act as a quality enhancer for automated builds and deployments. You must use it to deliver stable and working solutions continuously. Also, when you run automated smoke tests after each release, you will have fewer issues in the production stage.

Did you know fixing critical issues early is cheaper than addressing them in the production stages? This means another reason to conduct smoke tests! Make it a point to run them after all builds are released and when you make changes to your application.

Following these steps when you run a smoke testing cycle will help you get the best results.

Before you run a test, make sure you have your resources ready. If you run a manual test, your testers/developers must have ample time; also, if you plan on automated or hybrid tests, you should have your scripts or tools ready.

You must decide how many tests will be conducted and jot them down. After that, you should ideate on test scenarios and their associated functionalities. Once you have done that, develop guidelines with your developers and testers to ensure test consistency and synchronization.

Once you have everything in place, create a test with the essential features. Then, run the test and record the results to see if there are any defects.

The results of a smoke test are either Pass or Fail. If the test fails, send it to the developers again to fix issues. Once the issues have been resolved, test again to see if any problems have come up. Repeat the process till there are zero defects.

Smoke testing is a must for all your software development needs. However, the requirement doesn’t end here. You must run in-depth tests to deliver only the best solutions to your customers. We understand and have designed the best processes and techniques to offer top-notch quality assurance services. We first understand your requirements and then create a detailed test plan. This helps us maintain transparent communication and build trust with our customers. We enjoy clients’ trust across continents due to our top-notch technical expertise and business acumen. We specialize in

• Automated compliance monitoring
• A promise of 99.99% guaranteed uptime
• 24/7 threat detection and response
• AI-powered monitoring and analytics
• Comprehensive support for multiple testing frameworks and tools.
• Improved system performance with early defect detection

Let us understand how containerized testing environments can aid your smoke testing efforts. Initially, you can experience greater consistency, rapid deployment, and scalability. This is possible as containers take care of all application dependencies, which lets you ensure your test environment is the same as the production environment. With this, you can quickly validate your code changes in an isolated environment and boost software quality. To go further, tools like Kubernetes can be used to automate tests across multiple services. This way, you will be able to detect issues better. Last but not least, with containers, you get access to clean environments for all your tests. This way, the leftover artifacts have no impact on your test results.

Microservices can add to the complexities in smoke testing as they rely on multiple interdependent services. You must validate all dependencies to ensure your smoke testing efforts are perfect. This means your testers will need to check if the versions are compatible, if there is minimal lag in the network, and if there are any service failures to be considered. However, if microservices must be a part of your operations, then you need to adopt techniques like contract testing and API health checks. Also, containerized environments boost microservices testing efforts by letting you validate services before full integration, thus reducing the risk of failures in production.

Cloud-native applications are a unique blend of microservices and serverless architectures. Thus, since these environments are dynamic, they require you to implement specific smoke testing strategies. They can easily be deployed across multiple regions, interact with third-party APIs, and scale up/down as per demand. However, the catch is that all these aspects must be validated, and minimum latency must be ensured. Since containers and serverless functions are short-lived, building persistent test environments becomes tough. Businesses use Infrastructure as Code (IaC) to provide identical and temporary test environments before conducting smoke tests. Moreover, you must also use monitoring tools like AWS CloudWatch and Azure Monitor to ensure rapid detection of failed smoke tests before full-scale deployment.

Dealing with DevOps-driven workflows means that smoke tests are embedded in (CI/CD) pipelines. One of the approaches to smoothly run tests in these environments is the shift-left approach, where automated smoke tests run in the earliest stages of development. Another approach uses progressive deployment strategies. Only a few users receive the new version, and automated smoke tests monitor them for errors. If the test passes, further action is taken. Otherwise, an instant rollback is initiated. Often, developers and testers integrate observability tools to ensure all the smoke test failures are accounted for and debugged efficiently.

Here are some practices that will help you boost the efficiency and reliability of your smoke tests.
Manual tests can lead to multiple errors. So, it is essential to use automated test tools to validate core functionalities.

• Make sure you are not expecting a lot from your smoke tests. The focus should always be on checking the key features. Overloading them will only defeat their purpose.
• You must run tests after every application version to be 10x sure that your core functionalities work just fine.
• Documentation is the key to success and is also used for smoke testing. Maintaining a list of test cases and results can avoid common pitfalls and save time for other application versions.
• Stop wasting your time on repetitive tasks and instead use automation to save time and eliminate human errors.
• Conducting smoke tests in random environments is not beneficial. They should be run in environments that resemble production.
• Make sure to partner with analysts, testers, and developers to be thorough with critical aspects of smoke testing.
• While you may run your tests using virtual machines, containers, or cloud environments, consistency is the key to results.
• Run your smoke tests using continuous integration (CI) and continuous deployment (CD) pipelines to validate all builds.
• Smoke tests will occasionally fail. However, you must maintain clear logs and reports to identify issues efficiently.
• Last but not least, review test cases to ensure they are relevant as technology evolves.

Let’s see how you can integrate smoke testing into CI/CD pipelines with sample configurations.

Handling failures is a must with smoke testing.

• You can easily capture logs, generate detailed reports with frameworks like pytest or JUnit, and ensure easier debugging.

• If the test intermittently fails, you can retry it a few times before failing the build.

• If a smoke test fails, CI/CD pipelines should stop further stages and notify teams.

While you know the benefits of smoke testing, have you thought about how you can calculate its ROI? Well, here is the formula and steps you need to take:

Here are some of the metrics you need to know.

• Defect Cost Reduction

Here is the formula for calculating defect cost reduction.

Cost Reduction = (Avg. Cost per Defect x Defects Caught Early) – Late-stage Fix Cost

Let’s say the average cost you need to fix a defect in production equals $5000
At the same time, fixing it in the earlier stages cost $500.
Even if smoke tests catch 50 such defects annually, you will be able to save:

(50×5000)−(50×500)=250,000−25,000= $225,000

• Reduction in Deployment Failures

KPI: % of deployments that pass smoke tests without rollback

Let’s say if each rollback costs $10,000, and the percentage is reduced from 20% to 5%, the annual savings for all such deployments would come down to:

(20−5)×100×10,000= $150,000

• Time Saved per Developer

KPI: Hours saved in debugging and fixing production issues

Your developers may not have all the time in the world. Thus, it is essential to carry out smoke tests precisely.
If smoke testing reduces debugging time by 10 hours per developer per month and you have 10 developers who are earning $50/hour, the savings per year would be:

10×10×50×12= $60,000

• Faster Release Cycles

KPI: Reduction in time spent on manual verification

Yes, automated tests can help you cut time and errors in manual smoke testing.
Let’s say if automated smoke tests cut 2 hours from each release cycle, and there are 50 releases per year, with a $100/hr team cost. Here is how much you can save annually.

2×50×100= $10,000

• Customer Satisfaction & SLA Compliance

KPI: % reduction in post-release defects reported by customers

If customer-reported defects drop by 30%, leading to $50,000 fewer SLA violation penalties, your ROI will also increase.

Now that we have all figures, let’s look at the total calculations.

This means you can easily save $3.95 for every $1 spent. In the long run, you can look forward to improved software quality, long-term cost savings, and reduced failures.

Smoke testing can help you prevent failures when implemented in enterprise environments. Similar is the case with Amazon Web Services (AWS). Whenever multiple deployments are made across various regions, automated smoke tests check the system’s health before the final rollout. So, how does AWS manage all this? Well, it is done with canary deployments. In this arrangement, a few servers receive the update, and then automated smoke tests are conducted on critical workflows, database connections, and API health. If the system’s health is sound, the update is expanded gradually.

Another example is that of Netflix. It follows a microservices architecture to run containerized smoke tests in parallel across different clusters. Smoke tests validate whether streaming, user authentication, and recommendations work properly before full deployment.

We all know that industries like healthcare and telecommunications must abide by strict compliance rules. However, these rules can impact the efficiency of smoke testing processes. Banks and fintech institutions must adhere to PCI-DSS (Payment Card Industry Data Security Standard), so smoke tests must ensure that encryption protocols, API security, and authentication mechanisms also work. In the worst-case scenario, if the test fails, there must be provisions for immediate rollback and audit logging to maintain compliance. Also, regarding healthcare, compliance with HIPAA (Health Insurance Portability and Accountability Act) in the U.S. and GDPR (General Data Protection Regulation) in Europe is necessary. And how do smoke tests help with the same? They allow you to maintain vigorous access controls and ensure compliance with data-sharing regulations.

Let’s understand the differences between the two approaches of testing software.

While you may choose to conduct your smoke tests manually, these tools will make your job easier.

If you want a popular tool to automate your smoke tests, consider it complete with Selenium. It is a standard favorite of developers and testers as it allows excellent cross-browser and cross-platform compatibility. And the benefits don’t end there! Selenium also provides extensive support for automation frameworks. However, it has a drawback because it requires some programming and set-up time.

An ally to Selenium, TestNG is beneficial for Java applications. It is an ideal tool because it lets you easily group and prioritize tests. Moreover, you can conduct parallel tests and generate detailed reports to understand defects better. However, you will need to acquire programming skills related to Java to put this tool to the best use.

Designed for mobile apps, Appium will help you with hybrid, native, and web apps. Moreover, you get access to cross-platform capability only with a single codebase. Wait, there is more to it! Appium integrates well with CI/CD tools. The only drawback is that it is slower than other tools.

The best part about Jenkins is that it can integrate seamlessly with multiple testing frameworks and automate smoke tests. You can look forward to comprehensive testing and reporting logs with multiple support plugins. This is the reason why many software developers have unbreakable trust in Jenkins. However, you must shell out time to set up the tool.

AutoIt could be your pick if you are building a Windows desktop application. It makes writing scripts for basic UI actions easy and requires minimal setup. This application’s only limitation is that it caters to Windows applications.

Let’s understand the key differences between smoke testing and sanity testing.

While each model’s basics are the same, their approach is different. Some models suggest frequent and automated testing, while others suggest manual methods for specific instances.

• Smoke Testing in Waterfall Model: This model has been designed with stable software needs in mind. Each phase must be completed before proceeding to the next. As a result, a smoke test is conducted at the beginning of the test phase and the post-development phase. This is a blessing in disguise for testers, as it saves them a lot of time and ensures that all modules function smoothly at the basic level.

• Smoke Testing in Agile Model: Developers prefer this model because they get quick feedback on application defects. How is that helpful? It helps them keep the iteration process smooth. In this model, smoke tests are conducted at the start of each sprint after the build is created. This, in turn, helps ensure that new features work in sync with the existing ones.

• Smoke Testing in DevOps Model: This model emphasizes facilitating collaboration between development and operations teams. Thus, you can easily integrate automated smoke tests into CI/CD pipelines and ensure that only stable application versions undergo rigorous tests. Another benefit of using this model is that it helps you reduce downtime and helps your team prioritize their tasks.

• Smoke Testing in Incremental Model: Conducted in stages, this model involves conducting tests after each increment. This ensures that new changes do not break the established system. And how does this benefit your application? It lets you quickly provide the smooth integration of new functionalities and develop confidence in your application.

• Smoke Testing in RAD Model: As the name suggests, this model focuses on rapid prototyping and iterative development. By conducting tests efficiently, quickly, and flexibly, you can be twice as sure of your build quality. Another reason to use this model is that it will prevent a lot of rework, as you will address issues earlier.

When it comes to building software, reliability and profitability are of paramount importance. Smoke testing helps you achieve that and much more. Here is how you can implement it to boost growth.

Time and resources are the backbone of any business. There is no point in testing an application to find out the major features don’t work and that you need to redo everything. Smoke testing catches major issues early and helps you focus your efforts and time on core business processes.

A higher standard for software builds becomes a regular thing with smoke testing. You can build a better reputation in the market and look forward to increasing your prices and offering better benefits to your employees and customers.

Doing the same work again leads to frustration and poor spirits in your QA teams. Luckily, you can avoid this situation with smoke tests. It ensures that QA teams only work on reliable application versions and builds a conducive environment.

A study suggested that 98% of companies reported that a single downtime hour costs over $100,000; for some, it can go up to $1 million per hour. If you want to cut these losses and ensure that your solutions are free of bugs and zero outages, make smoke testing your best ally. Not only will it help you eliminate such incidents, but it will also help you build a solid business reputation.

It is productive work that yields high ROIs. Without smoke testing, testers waste time on issues caused by fundamental defects. However, when you conduct these tests, you ensure only stable builds go forward for deeper tests. This way, you save time for developers, and they can use it for better pursuits.

Smoke testing in software testing improves quality and stability verification and saves time and resources. Addressing the discussed aspects can streamline your application development process. Also, when you know that the software quality is top-notch, you can look forward to expanding your service across industries and seeing a significant increase in your revenue margins.

As word of mouth spreads, your clientele will increase, and you can look forward to working with global clients and expanding your technology portfolio. BuzzClan provides top-notch QA support and tools to help you achieve all this and much more, fulfilling your business goals without compromising quality and operational excellence.