Unleashing the Power of Parallel Testing in Test Automation

Understanding parallel testing in automation

Parallel testing in the era of Test Automation refers to executing multiple automated test cases/test suites simultaneously. Thus, it dramatically reduces the test execution time and gives faster feedback on the quality of the application.

The beauty of Parallel Testing is that tests can be executed simultaneously in multiple environments using different browser configurations.

Sequential automation testing

The below diagram illustrates how the test run happens in the traditional Sequential Automation Testing model; requiring each test suite to be completed before the next can start, similar to the Waterfall methodology.

Parallel automation testing

Whereas this diagram illustrates how the test run is performed in the more efficient Parallel Automation Testing model where each test suite can be ran simultaneously. 

Advantages of parallel test automation

• Accelerated Test Execution: The main advantage of Parallel Testing is concurrent and simultaneous execution of multiple test cases, thus drastically reducing the overall test execution time. This speedup in execution time ensures quicker identification and resolution of defects.
  
  
• Optimised Resource Utilisation: By distributing test cases, parallel testing ensures efficient utilisation of testing infrastructure, minimising idle time and maximising productivity.
  
  
• Scalability for Large Test Suites: As test suites grow, maintaining efficiency becomes highly challenging for the QA team. Parallel testing addresses this by offering scalability to ensure consistent performance, even with extensive test suites.
  
  
• Efficient Regression Testing: Parallel execution is particularly beneficial in regression testing, where a large number of test cased need to be executed after each code change. It allows for a faster feedback loop, crucial for maintaining software stability.

Optimising test execution time in parallel testing

Let’s talk about optimising the test execution in Parallel Testing; consider a scenario where 20 runners are participating in a test, each assigned a lap of varying length. The objective for each runner is to complete their dedicated lap. The test is not a race but focuses on runners completing the laps within a specified time.

After the run begins, it is observed that five runners finish their laps within 5 minutes, another five runners within 10 minutes and yet another five runners within 15 minutes. The remaining five runners take more than 15 minutes to complete their laps.

Parallel testing, as implemented in the example mentioned above, can be likened to a scenario where the runners represent test suites. In this analogy, each test suite initiates simultaneously, resembling the synchronised start of the runners. Much like the completion time of laps varied for the runners, the completion time of test suites may also exhibit variability.

In the context of parallel testing, an analysis of completion times reveals that there is a subset of five runners whose laps exceeded the 15-minute mark. To optimise the completion process, a potential approach is to subdivide these longer laps into seven or eight segments and consider increasing the number of runners.

To optimise the completion time, a strategy akin to dividing the longer laps for the runners is employed. Similarly, in the Parallel Testing context, test suites can be subdivided further, allowing for parallel execution of smaller segments. This approach aims to ensure that each test suite completes within the expected period, mirroring the goal of having runners finish their laps within a designated time. The example highlights the use of parallel testing to efficiently manage and optimise testing processes based on observed performance metrics.

This strategy aims to balance the overall completion times and make the distribution uniform across the test suites. However, the decision to increase the number of test suites should be made considering factors such as the testing environment's capacity, available resources and the specific objectives of the testing scenario.

By implementing this parallel testing strategy, the overall testing time can be further reduced. The parallel execution of smaller test suite segments enhances efficiency, similar to how breaking down longer laps improved the overall completion times for the runners. This comparison underscores the parallel testing approach as a means to achieve more predictable and optimised testing cycles.

Tools and technologies

Choosing the right tools and frameworks is pivotal for successful parallel testing in automation. Popular choices include Katalon, Selenium Grid for web applications, TestNG and JUnit for Java-based projects and tools that support parallel execution in other programming languages.

Best practices for automated parallel testing

• Create Independent Test Cases: Design test cases to be independent of each other to enable parallel execution. Ensure one test case run does not conflicts with the other.
  
  
• Keep optimising the Test Runs: Optimise the test suite length in a continual way until the test run length are within expected timeframes. This is achieved by using various strategies such as breaking down larger test suites into smaller and more manageable segments.
  
  
• Efficient Test Environment Configuration: Configure test environments to handle parallel test execution seamlessly, avoiding bottlenecks and contention for resources.
  
  
• Handling Test Data in Parallel Executions: Implement dynamic test data management strategies, such as generating unique test data for each parallel execution or utilising database isolation.

Future trends in automated parallel testing

In the ever-evolving world of Automation Testing, parallel testing is no exception. Emerging trends include the rise of cloud-based parallel testing services, the integration of artificial intelligence for test execution optimisation and advancements in technologies for creating isolated test environments.

Time to act

Ready to boost up your test automation with parallel testing? Want to learn more about CTG's Automated Testing Solutions? Speak to a member of our team. Contact us.