Robustness Testing in Software Testing – An Overview

Let’s talk about something important in the realm of software testing: Robustness testing. ISTQB states, “Robustness testing is the degree to which a component or system can function correctly in the presence of invalid inputs or stressful environmental conditions.”This is when we test a system or program to see how well it can handle unexpected scenarios and mishaps.

We want to ensure that our software can keep soldiering even if it encounters unexpected situations, like a power outage or memory overload. Nobody wants their system crashing during an important project!

So, in this blog, let’s look at this testing technique in detail and why it matters so much in ensuring top-notch performance from our software applications.

What is Robustness Testing?

Robustness testing is software testing that evaluates the capability of a system to operate correctly in unexpected or abnormal conditions. This type of testing is designed to identify possible failures due to unexpected inputs or errors, such as invalid data, network interruptions, or power failures. The goal of robustness testing is to ensure that the system can handle errors and maintain its functions without crashing or becoming unstable, thereby maximizing the software’s reliability and reducing the risk of failure.

Why is Robustness Testing important?

Here are ten important reasons why robustness testing is important:

1. It uncovers hidden bugs that can cause malfunctions.

2. Improves the reliability and quality of software.

3. Increases customer satisfaction by preventing software crashes.

4. Helps to predict real-world scenarios for better preparedness.

5. Validates the security features of the software.

6. Identifies code weaknesses and restrictions that can be optimized.

7. Enhances the overall software performance across various platforms.

8. Helps to save time and money by avoiding costly bug fixes.

9. Promotes software longevity since it can withstand changes in operating environments.

10. Boosts user confidence in the software by assuring stable and consistent performance.

Types of Testing to Ensure Robustness of Test Suites

Different types of testing must be done to ensure the robustness of test suites. Here we give you a list:

1. Functional testing – Verifies the software’s desired behavior under various scenarios. Functional testing conducts numerous tests that examine all software functionalities.
2. Regression testing – Ensures that software changes do not result in unexpected outcomes in previously tested functionality. Regression testing ensures the software application works correctly even after changes or updates.
3. Load testing – Examines software performance under various loads and conditions to ensure it can support expected user volume. So this type of testing simulates production loads by subjecting software to a series of tests to ensure it can handle expected traffic.
4. Fuzz testing(Fuzzing Test) – Sends malicious input to the software to discover vulnerabilities and unexpected behaviors. After conducting fuzz testing, the program is observed for crashes, failed code assertions, and possible memory leaks.
5. Mutation testing – Changes the software’s code to see if the test suite can detect these changes and identify issues. Mutation testing aims to detect coding or input flaws that can result in incorrect program output.
6. Black-box testing – Tests the software’s external behavior without knowing its internal workings. The tester knows the intended output of the software but lacks knowledge of its internal workings. Functionalities, user interface usability, and conformity with external standards can all be tested using black-box testing.
7. Security testing – Verifies the software’s resistance to attacks and potential vulnerabilities. Conducting security testing can help in identifying probable security threats.
8. Use case testing – Examines the software’s functionality from the perspective of user scenarios. Conducting Use case testing can help in identifying potential usability issues.
9. Negative testing – Tests how the software behaves when presented with invalid inputs and unexpected situations. It can reveal input handling or validation mistakes that may result in data loss or leave security gaps.
10. Stress testing – Evaluate the software’s increased workload capabilities under heavy load and usage. So, it can detect concerns during intense pressure or heavy workload.

Robustness Testing Scenarios

Specific scenarios can cause software failure due to a lack of software robustness. The scenarios that can be tested are:

1. Test for handling large amounts of data.

2. Test for unexpected inputs and edge cases.

3. Test for system failures and recovery.

4. Test for long periods of sustained usage.

5. Test for compatibility with various hardware and software environments.

Should Robustness Testing be Automated?

The robustness of an application should be tested. But should you automate those tests? Only when you know, automation helps you in some way – it could be to save efforts, time, or resources.

Robustness Testing Tools

One of the most important factors for achieving an ROI on test automation is the tool used for test automation. Robustness testing tools are software testing tools that help automate the robustness tests for an application. Examples of such tools include:

• Testsigma is a cloud-based test automation platform that enables teams to automate their tests for web, mobile, APIs, and desktop applications. With Testsigma, teams can easily create and edit automated tests using simple English. Thus, It allows testers to focus on testing and defect hunting while the automated tests run in the background. Testsigma offers enhanced security, an extensive test lab, project and review management, powerful reporting capabilities, and more. It also offers a range of features for test management, including test case management, test suite creation, and test execution reporting.


• JMeter is an open-source load-testing tool that helps create web application test plans. It simulates a heavy load on a server, network, or object to test its performance under different conditions. JMeter can measure the performance of static resources such as HTML and dynamic resources such as JSP, Servlets, and AJAX. It supports various platforms like Windows, Mac OS X, Linux/Unix, etc. With the help of the JMeter approach, users can create test plans with multiple threads and configure them to run at different intervals. This helps in analyzing the application’s performance under varying loads and conditions.


• Selenium is an open-source automation testing tool used to test web applications. It can automate user interactions with a web application by clicking buttons, entering text into forms, and verifying its output. Selenium supports multiple programming languages and platforms, including Java, JavaScript, Ruby, Python, and C#. Using Selenium’s APIs and libraries, testers can create automated tests for their web applications that can be run repeatedly without manual intervention.


• Appium is an open-source test automation framework for mobile applications. It allows developers to write automated tests for their apps on multiple mobile platforms, including Android and iOS. Appium supports many devices and provides an intuitive API that makes setting up and running tests quickly easy. With Appium, developers can write tests in any language they prefer, such as Java, Python, Ruby, or JavaScript.


• Loadmeter is a cloud-based platform that provides an efficient approach to helping organizations monitor their application performance. It helps organizations identify and address potential issues before they become critical. Loadmeter supports various platforms, including Windows, Linux, Mac OS X, and Android. With its intuitive interface and powerful analytics capabilities, Loadmeter helps organizations reduce downtime and improve the overall performance of their applications.

Benefits of Robustness Testing

1. Ensures software reliability: Robustness testing identifies potential weaknesses in the system, making it more reliable and less prone to crashes or failures.

2. Enhanced user experience: Robustness testing ensures the software can withstand unexpected inputs and deliver optimal performance, improving user experience.

3. Reduced maintenance costs: Robustness testing helps identify potential issues early in the development process, thereby reducing maintenance costs.

4. Prevents data corruption: Robustness testing ensures the software can handle unexpected input data and prevent data corruption.

5. Increased security: Robustness testing ensures that the software can withstand security attacks, preventing unauthorized access or manipulation of data.

Summary

In summary, this blog post on robustness testing provides valuable insights into various practical aspects such as executing tests, defining stress and load testing scenarios, and its benefits in bringing reliability and stability to software systems. A well-executed robustness testing improves the quality and instills confidence among the users while using critical applications.

Frequently Asked Questions

What tests the robustness of a test?

The robustness of a test refers to its ability to perform consistently and accurately under various conditions, including different sample sizes, types of data, and potential measurement errors. To evaluate the robustness of a test, it must be subjected to several tests.

What is an example of robustness testing?

Test an application’s ability to handle incorrect user input.

A user enters an invalid date format into a date field,(If the required format is “mm-dd-yyyy” and the user enters “dd-mm-yyyy” ). For example, the user enters the date field as 03-30-2023 instead 30-03-2023, and the application should be able to recognize this as an error.

Robustness testing ensures the application can handle any unexpected input without crashing or losing data.