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Load & Performance Testing Ensures Your Application’s Resilience

Like a check engine light on system performance, load and performance testing tools test under regular and extreme loads to find any faults and ensure your application performs as expected under diverse operating conditions.

What Is Load & Performance Testing?

Companies are under pressure to deliver an excellent customer experience. You must ensure your software responds reliably, correctly, and consistently, regardless of usage load.

Performance testing assesses how an application behaves under specific conditions and analyzes the results so you can identify and address any bottlenecks or blockages that prevent smooth operation.

With a load and performance testing strategy, your applications can be better prepared for unexpected demand. Load and performance testing tools ensure your system handles sudden bursts in traffic and delivers a superior user experience.

Why Is Load & Performance Testing Needed?

Most days, your application functions under normal conditions. But once in a while, the load peaks, or the performance of a dependent system dips.

Many organizations only perform tests against a subset of the potential conditions that users could experience. Agile teams recognize that they need to run performance tests against a variety of workloads to meet user expectations.

Performance and load testing tools are a check engine light on system performance. They test under regular and extreme loads to find any faults and ensure your application can take the heat. Test automation makes it easier and faster to run a combination of performance testing steps in parallel.

Take aim at performance issues with load testing. Check out our webinar to learn how to customize virtual user configurations, simulate loading in your test environment, and review and analyze performance trends over time.

Benefits of Performance Testing

Performance testing provides numerous benefits. Here are some of them.

Verifies the Core Features of Your Software

A strong software foundation is key to software success. Ascertaining the performance of the software’s basic functions enables management to make essential decisions based on the success, or failure, of the software’s performance. Conduct performance testing as a critical subset of your overall application testing strategy.

Measures the Accuracy, Speed, & Stability of Your Software

Each test measures a particular aspect of the performance and generates testing results for analysis. This allows you to view the vital parts of the software under normal and peak resource usage, giving you data on how the program handles scalability. The data, gauged against known, baseline standards, allows developers to make intelligent decisions about needed changes.

Verifies Operation Under Stress

Software testing for load and performance often predicts behavior and can help DevOps plan for unexpected or unusual circumstances. It is important to find out early whether your organization can manage scalability. Using testing methodologies sooner rather than later helps testers maximize performance and hone capacity to manage demand.

Can Assure User Satisfaction

A favorable first impression of potential customers is crucial. Research indicates almost half of all users rely on mobile and web service applications to load in two seconds or less. Your software has this tiny timeframe to make a good show to potential users before they sign off. Load time can accelerate as network capacities and connection speeds rise.

When you measure performance, it allows you to monitor how customers respond to the software. This provides an advantage because you can identify critical issues—before your customers do.

Identifies Inconsistencies & Helps Resolve Problems

Performance testing provides a cushion for developers before they release the software. Problems often magnify after release; this testing plan irons out any issues. It’s important that teams monitor performance testing across all business divisions, so decision-makers have open channels for communicating with IT, thus making sure software performance matches business strategies.

An adequate staging environment for testing allows more time for improving technology as opposed to fighting fires in avoidable, pre-existing issues. These issues can grow rapidly and simultaneously become expensive after the software is in the customer’s hands.

Types of Performance Tests

Many types of performance tests exist. Test design may vary based on the purpose of the test. We include a number of the important testing types here.

Load Testing

These tests simulate the approximate number of users that may use the application. When reproducing representative expected load and usage conditions, centered on response times, load tests help pinpoint possible bottlenecks. The test enables developers to assess whether applications meet expectations for responsiveness and stability based on the load generated.

Volume Testing

Also known as capacity testing. When testers use load testing, they populate large amounts of data in a database and monitor the behavior of the system overall. The purpose is to observe the performance of the software’s applications under various database volumes.

Stress Testing

This entails testers testing the application under extreme workflows, which enables the testers to observe how the application handles large volumes of data processing or high traffic. The idea is to identify the application’s breaking point.

Endurance Testing

Also known as soak testing. Testers use this test to ensure that the software can handle the specified load over extended amounts of time. This can also check to ensure that memory leak issues don’t occur after the application runs for long periods.

Spike Tests

Testers employing these testing measures seek to understand the implications to a system’s operations when activities on the system are above the norm. In contrast to stress tests, these tests consider the complexity of actions the system performs, and the number of users involved, which then yields an increase in the number of business processes the system generates.

Scalability Testing

Bottlenecks occur when there isn’t enough capacity to handle the workload. Testers use scalability testing processes to discover the software application’s ability to “scale up” to handle user load increases. This helps them plan for any addition in your software system’s capacity.

Load Times

Load time means the length of real time a system requires to start an application. It’s best if it’s short—if possible less than a few seconds. Some applications, however, may require as long as a minute.

Response Times

Response time is the time required for the application to put out a reply after a user inputs information into the app. A number of studies, including this one, link short response times to high user satisfaction.


Poor scalability means a software application cannot accommodate the range of user types or the number of users the developers expected it to handle when they created it. Testers use load testing to make sure the app can do what it is supposed to do in terms of numbers and range.


When a system has bottlenecks, the result is system latency and poor performance overall. It happens when either hardware problems or coding errors produce a decrease in throughput under specific loads. Often just one bad section of code can cause bottlenecking. To remedy it, developers need to find and fix the area of code that is causing bad performance or add more hardware. Common performance bottlenecks include CPU, network, and memory utilization; operating system limitations; and disk usage.

Performance Testing Best Practices

Here are some best practices for performance monitoring and testing.

  • Thoroughly understand the application. What are its capabilities, intended use cases, and the situations under which it is supposed to thrive?
  • Thoroughly understand the different types of tests (mentioned above) and how and when to use them.
  • Take into consideration all possible product environments and devices, including browsers and operating systems.
  • Use DevOps. Involving DevOps brings together the test plan and development teams. This helps to identify errors quicker and resolve them sooner.
  • Establish your test environment and tools for validating application performance. Isolate it from the user acceptance testing (UAT).
  • Define base operating criteria for success and extend them to extreme conditions under which operation should be maintained.
  • Design performance tests. Leverage API testing scenarios for performance testing and customize them as needed.
  • Configure the performance testing environment, perform the tests, and collect the results for analysis.
  • Review the results, identify performance areas to address, and repeat the process (retest) as needed.
  • Triage the performance problems. Involve all concerned parties: testers, developers, and operations people.

How to Get Started & Examples

The application you build has both functional and nonfunctional testing requirements. Load and performance testing best practices are a necessary aspect of software development but especially so when load can vary with sudden swings in demand and network traffic.

Get a head start by using your existing API test scenarios as a basis for performance testing. Parasoft’s solution creates rich multi-profile performance test scenarios from your functional testing assets.

Test Case Examples

  • Verify that the response time is 4 seconds or less when 1000 users (or virtual users) simultaneously use the website.
  • Verify that the application’s response time under load is in a range that is acceptable during slow network connectivity.
  • Observe the maximum number of users the application can support without crashing.
  • Record the database’s execution time when it reads or writes 500 records at a time.
  • Check the database and application server’s memory and CPU usages during peak load situations.
  • Check the application’s response time during low, moderate, and high load conditions.

Using these test cases in actual performance testing scenarios, you will find that specific numbers replace vague terms such as “heavy load” and “acceptable range.” Testers set the performance criteria numbers taking into consideration the application’s technical landscape and the project’s business requirements.

Why Parasoft?

Put Performance in Context

There are many reasons tests fail. Not every problem points to a fire. Parasoft’s load and performance testing tools test end-to-end application performance, placing performance problems in the context of the user experience. This allows you to tell when there’s an actual fire, assess its impact, and determine the best approach to extinguish it.

Seamlessly Test Across the Entire Application

You don’t have to deploy a specialty tool for load and performance testing, another to test APIs, and a third for web UI testing. Parasoft test automation solutions do them all so you can deploy an integrated testing suite that works seamlessly across all interfaces.

Create One Scenario, Use It Multiple Times

You don’t need to create separate scenarios for functional and load and performance testing. Instead, Parasoft allows you to reuse the same API test scripts for multiple testing purposes, saving you time, effort, and money.

Leverage Historical Performance Data

Parasoft’s load testing reporting dashboard allows you to study historical performance testing data easily and leverage that intelligence to develop smarter. View and analyze testing results to determine risks and next steps.

Make Performance Testing Relevant

Match your user profiles to how they use your application. Apply loads that simulate such a scenario, so your load testing is personalized to your user base. This modeling also tells you how specific user experiences will be impacted under heavy loads, so that you can prepare for it and support your customers.

Predict Performance Issues

When running Selenium web UI tests, integrated smart analytics aggregate the test results and provide performance goals or benchmarks to generate early warnings for performance issues in your web applications.

Frequently Asked Questions