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4 Types of Functional Testing and When to Use Them

Kelly Lyons

As discussed in my last blog, functional testing is a great way to ensure that your software is bug-free and ready for launch. But what type of functional testing should you use? The answer to this varies greatly depending on your product and your goals. Below are four of the most common types of functional testing and when you should consider using them.

Capture Large Defects with Smoke Testing

Named for its likeness to hardware smoke testing—where testers are looking to see if a product literally smokes when turned on—smoke testing is perhaps one of the most vital tests you can perform. Done early in the process, this type of testing checks if major pieces of the software work well enough to move on to the next stage of development or testing.

Smoke testing can either be automated or done manually. Often, the first time it's done manually so testers and developers can understand where the problems lie. After the initial test, the test can be automated as part of a continuous build process. If the product fails to pass the test, that signifies that it’s time to go back to development. This process will repeat until, eventually, the product passes all the tests, indicating that it’s ready to be staged, tested for performance, and finally, regression tested (which we’ll touch on later).

Check Logic with Sanity Testing

Often confused with smoke testing, sanity testing checks the rationality of your product after it’s gone through the smoke testing process. Does it work as it should? Have any of the changes made created other new, severe issues in the product’s functionality? These are the questions that sanity testing aims to answer. Unlike a smoke test, a sanity test is typically performed by a human tester with knowledge of what has changed in the application. Performing both smoke testing and sanity testing early in the process ensures your team doesn’t spend too much time working on something that will ultimately need to be changed entirely because of more significant bugs.

Ensure Your Product Can Meet Users Where They Are with Compatibility Testing

After you’ve smoke tested and sanity tested, it’s crucial to check that your product can work on the hardware, software, operating system, or devices that it should. For instance, you may have created a new mobile game – but does it work for both Androids and iPhones? What about older versions of each of these products? And how does it look on a tablet? With compatibility testing, you can entrust that everything works where it should work.

Compatibility testing, in particular, is where crowdtesting shines. By working with a crowdtesting vendor, you can test your product on a variety of devices, software versions, networks, among others, to ensure that it works on all of the systems that it should work on.

Regression Testing

The last piece in the puzzle, regression testing, is often thought of as a more in-depth version of smoke testing. It comes after all the previously mentioned tests and determines whether code changes have actually fixed bugs or if they’ve even created new ones. Not only can it be used to make sure that large pieces of code are working correctly, but ideally, it can be employed routinely after any change is made to the code to ensure that nothing was broken during the upgrade.

Unfortunately, many development teams don’t have the bandwidth to perform manual regression tests after each change. In those cases, they should seek out the help of both automated testing and crowdtesting. With automated testing, teams can test more faster and accurately. Like everything in the testing space, it’s not without nuance. The quality of regression tests depends on the quality of their design. It’s all too easy to design a test poorly when you don’t know what bugs you’re looking for. 

Functional Testing with Crowdtesting

With crowdtesting, you can harness the power of dozens—if not hundreds—of people to deal with the more volatile and subtle tests. By setting up automated tests to deal with larger issues, you can use the power of the crowd to find masked defects. Only humans can truly understand human behavior, making them uniquely able to detect issues that machines aren’t capable of catching.

Another added value they bring: they can suggest ways to make improvements. This saves a great deal of unnecessary coding time during further development. 

Functional testing efforts today can help you reap the benefits tomorrow. By functional testing early—and often—you can resolve problems faster, saving your team time and money and ultimately creating a better user experience. Crowdtesting further enables functional testing to find problems the developers didn’t anticipate. Rather than simulating the real-world user interaction with the software, crowdtesting sees informed, experienced professional testers anticipate the user experience on various devices and platforms in diverse locations.



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