What is Parallel Testing? – A brief introduction

Modern development practices use continuous integration and testing for a faster and more efficient workflow. Sequential testing is the norm, but parallel testing allows the process to speed up further while remaining efficient.

What is parallel testing? This is a testing method that enables QA to execute multiple test cases simultaneously in different environments or with different codebases. It is a semi-automated process, which often involves using virtual machines. The tests consist of two or more elements that check an application’s features simultaneously on individual computers.

Parallel testing relies a lot on the cloud platform. Cloud technology offers several features that make it easy to run tests without investing a lot in the infrastructure. The cloud lets testers examine numerous configurations simultaneously, with the devices being easily accessible anytime from anywhere.

Parallel testing is an easy solution to bring down the cost and reduce the total testing time by simultaneously running tests, with the primary objective being saving time.

Benefits to Parallel Testing

Parallel testing is helpful when the system needs testing on different operating systems, browsers, and devices.

  1. Reduces Test Execution Time – Running simultaneous tests using parallel testing instead of consecutively running them helps complete the tasks much faster. Parallel testing speeds up the execution and shortens the overall testing cycle. Since more can be achieved in less time, this method is helpful when working to a strict timeline. If the system needs to be tested against X number of devices, the tester will need to write the test script just once because the same script can be run on all the required devices, which cuts the overall testing time.
  2. Faster Feedback Cycle – When test execution speed increases, it also improves the feedback cycle. More instantaneous feedback assists in a quicker fix. By performing the tests in parallel, retesting fixes can be picked up as the development team updates.
  3. Better Coverage – When tests are run in parallel, testing time is reduced, which presents opportunities for including additional checks and multiple configurations. Parallel testing always adds value because it takes the test coverage to the next level, ultimately giving a good ROI.
  4. Broader Compatibility – Parallel testing offers a significant advantage in isolating cross-platform related issues. Because tests run on independent browsers and OS, each provides distinct information about any platform failures.
  5. Cost-Efficiency – Creating and maintaining a test environment is always hard on the pocket, but maintenance becomes a lot easier when the same feature is available on the cloud. Parallel testing in the cloud offers several advantages. It reduces the overall cost of maintaining a test infrastructure, especially when the release is delayed or an extended testing cycle.

What is parallel testing?

Quick Tips for Optimizing Parallel Testing

Transitioning is best done in phases, although this method will not be suitable for every kind of test. Start by identifying tests that are an obvious fit, then gradually expand the scope.

Determine Test Conditions

Parallel tests come into the picture when testing requires testing multiple combinations. Due to the ever-growing numbers of devices and browsers in use today, testing is an increasing challenge. The various tools used for parallel testing can run tests on almost all devices. Therefore, it’s advisable to determine the test conditions and configurations needed. Focus on essential areas instead of running through the tools’ entire options at the planning stage.

Check the Test Data Dependencies

With tests designed for sequential testing, it’s possible that data generated in one of the test cases may work as an input for others.

Test scripts have dependencies. When tests are run sequentially, dependencies can be subtle because the tester knows the order in which the scripts execute, then update data. With parallel testing, awareness of these dependencies becomes more of a challenge. A workaround would be to design test cases that include independent test data generation. Scripts must include steps for configuring and creating data.

Keep the tests Atomic and Independent

When designing tests for parallel execution, be sure to create the tests as entirely independent from each other. Doing this will eliminate the constraints of running tests in a particular order, enabling you to run them at any time on any device. Moreover, since an atomic test concentrates on just one area of the application, debugging is more straightforward, allowing developers to quickly locate the source of the failure.

Utilize Cloud-Based Environment

One of the biggest challenges in parallel testing is creating a testing environment. Hosting or maintaining an infrastructure is costly and doesn’t provide all the resources needed for this kind of testing. Keeping the testing environment up-to-date is another tedious task. A cloud-based environment offers a range of resources and is a preferred, cost-effective solution. Using the cloud allows continuous test execution, so testing can begin as soon as the developer updates the code.


The need to stay up to speed with rapidly changing technology exists irrespective of the software methodology used within the projects. Parallel testing is an excellent approach to achieve speed enhancement. With parallelization, organizations benefit from reduced QA expense, optimized processes, and continuously improving tests for faster results. Parallel testing improves quality and helps to release the product more quickly.


Priya Rani

An Enthusiastic QA Expert who loves to share knowledge and experience through blogging.