What Is System Testing - An Ultimate Beginner’s Guide 2024

QASource Engineering Team
QASource Engineering Team | January 9, 2024

What Is System Testing: An Ultimate Beginner’s Guide

Regardless of the industry vertical, it is prudent for businesses to test their systems before going live to the public. This way, it’s easy to ensure efficiency and avoid expensive mistakes. System testing is the last line of defense before releasing a product. It's also the most comprehensive type of testing because it covers everything from business requirements to the end-user experience.

What Is System Testing?

System testing is the process of verifying the end-to-end behavior of a software application. System testing aims to identify errors, gaps, or missing requirements in the overall functionality of the software application.

It is usually done after all the unit and integration tests are completed. Testing the software application before releasing it to end users is essential.

System testing can be accomplished internally by your business, but you can also outsource it to experts like QASource, who have extensive experience in the entire process.


Objectives of System Testing

These are the primary goals of system testing:

  • Reducing Risks: System testing is one of the final and most critical steps in verifying the quality of your software before it goes live. Identifying and addressing these issues before release can help reduce risks and ensure a smoother rollout for your users.
  • Preventing Defects: System testing is verifying the functionality of a complete and integrated system to determine if it meets the requirements specified in the system specification. System testing aims to identify errors, gaps, or missing requirements in the tested system.
  • Verifying Design: System testing is used to check whether or not the system has been designed according to the correct specifications.
  • Validating the System: System testing is the process of verifying the completeness and accuracy of a system. One of the main objectives of system testing is to provide confidence that the system meets its requirements and performs as expected.


Different Types of System Testing with Use Cases

Mentioned below are the different types of system testing:

  • Usability Testing

    In usability testing, the system is tested for user-friendliness. Testing participants are given some tasks to perform using the system. Their performance is observed, and any problems they face are noted.

    • Use Case: Assess the user interface of a customer relationship management (CRM) system for intuitiveness.

    • Testing Scenario: Conduct user feedback sessions to evaluate ease of navigation and the overall user experience.

  • Regression Testing

    It’s important to ensure that new system changes don’t break existing functionality. This type of testing compares the system's current behavior with its behavior in a previous version.

    • Use Case: Ensure that a software update does not introduce new defects in a payroll processing system.

    • Testing Scenario: Re-run a set of previously executed test cases after implementing changes to verify system stability.

  • Performance Testing

    Performance testing is conducted to evaluate the compliance of a system or component with specified performance requirements. It determines whether a system meets its performance objectives, such as response time or throughput.

    • Use Case: Evaluate the response time of a banking system during peak transaction hours.

    • Testing Scenario: Simulate many concurrent user transactions to assess system responsiveness.

  • Functional Testing

    It checks whether or not the system meets the requirements — especially for its features. Functional testing can be done manually or using automation tools.

    • Use Case: Verify that the login functionality works correctly in an e-commerce system.

    • Testing Scenario: Test user authentication, password reset, and account creation to ensure proper functioning.

  • Recovery Testing

    This type of system testing is conducted to check if the system can recover from crashes, hardware failures, and other catastrophic problems. It measures how well the system can handle unexpected inputs and events.

    • Use Case: Assess the ability of a document editing tool to recover files after a system crash.

    • Testing Scenario: Simulate system failures and verify that the application can recover data without loss.

  • Migration Testing

    It is testing how well a system can support moving from one environment or infrastructure to another. This type of testing is important because it ensures systems can be properly migrated with minimal disruption.

  • Regression Testing

    It’s important to ensure that new system changes don’t break existing functionality. This type of testing compares the system's current behavior with its behavior in a previous version.

  • Hardware/Software Testing

    It can be done on hardware or software. All the hardware components are tested to see if they work together as intended. This might involve testing the system’s wiring, power supply, and input/output devices.

    Software testing is a little different. In this case, the system’s functionality is tested without regard to its physical components. All the software that makes up the system is tested to see if it performs as expected.


How We Plan for System Testing

There are different levels of software testing. As such, you must plan for it meticulously by:

  • Setting Up the Environment for Test Case

    It's important to set up the test environment before writing test cases. This includes specifying the testing tools, programming language(s), and frameworks that will be used and setting up any necessary configurations and dependencies.

  • Creation of Test Case

    Next, you must consider the creation of a test case. The test case contains all the specific details about what you need to test and how you will test it. The document should also include what constitutes a pass or fail for each test.

  • Creation of Test Data

    After the test case comes the test data creation. This data is created considering the inputs and outputs of the test case. This data can be both positive and negative. While creating test data, one has to be very careful so that all the critical fields are covered, and no important field is left out.

  • Running the Test Case

    You should then have a strategy for running the test case, which will give you an output. The output will show whether the test case has passed or failed.

  • Defect Reporting

    The test case should show the system's behavior when encountering an error or defect. We must understand how defects are reported and fixed to plan for system testing properly.

  • Regression Testing

    Regression testing verifies that new features haven’t introduced any new bugs and existing functionality hasn’t been broken. This process can be automated with tools.

  • Fixing Defects

    Additionally, having a plan on how to fix defects is important. Not every defect can be fixed, but having a process to evaluate and fix them is key to success.

  • Retesting

    Once a tester has found and documented a defect, the development team should fix it, and then the tester should verify that the fix works as expected. If you don’t do this, you risk having undetected defects in your software. You have to plan for complete or selective retesting when necessary.


Factors to Keep in Mind While Planning For System Testing

Some critical factors to remember as you plan for system testing:

  • Industry Type

    Know the industry vertical to which your company belongs to understand the testing process and ensure you have the resources to complete the task.

  • Time Required

    You must know how much time you can dedicate to testing. This will help you schedule your work and give you a realistic idea of the progress.

  • Resources Available for Testing

    As mentioned, consider your test team’s size, skills, and experience while planning for system testing. Depending on the size of your application and its complexity, you may need to hire more testers or train your existing staff.

  • Experience of Tester

    Considering testers' experience while planning for system testing is essential. If the testers are new, more time might be needed to complete the test cycle. On the other hand, less time is required if they have prior experience.

  • Overall Cost for Testing

    System testing can be prohibitive, and keeping the overall cost of testing in mind while planning your test strategy is essential. Many factors can affect the cost of system testing, such as the size and complexity of the system, the number of test cases required, and the amount of time and resources required to execute the tests.


How Can QASource Help You with System Testing?

QASource can be a valuable partner in facilitating and enhancing the system testing process. As a specialized quality assurance and testing service provider, QASource offers a range of capabilities and expertise to ensure the success of your system testing endeavors. Here's how QASource can assist you with system testing:

  • Leverage the expertise of our testing professionals to define a comprehensive test strategy tailored to your system testing requirements.
  • Conduct thorough risk assessments to identify potential challenges and develop mitigation strategies.
  • Implement robust test automation frameworks to expedite test execution and enhance test coverage.
  • Conduct in-depth root cause analyses to identify the underlying issues causing defects and prevent their recurrence.
  • Experience proactive communication and collaboration throughout the system testing lifecycle.

The Tools We Use

Here are a few system testing tools that you can use:

  • Robot Framework

    It provides several built-in tools and libraries, but you can also create new ones. Its operating system and application are independent. The core framework is implemented using Python, but the standard library also has Java and .NET interfaces.

  • JMeter

    It is a powerful testing tool for web applications and services. It can simulate heavy loads on a server, network, or object to test its strength or analyze its performance under different load types.

  • Selenium

    It is a free, open-source, automated testing framework to validate web applications across browsers and platforms. It provides a record/playback tool for authoring tests.

  • Gallen Framework

    It is a tool that allows for system testing automation. It's an open-source tool that can be easily integrated into our development process. In addition, it supports a wide range of applications and platforms.



What is system testing in software engineering? It’s the process of verifying that a system meets its requirements. By running tests on all components and functionality, software developers can ensure the system will work as expected when deployed. System testing is essential to quality assurance and should be done early and often during software development. If you don’t know where to start, you can enlist the help of professionals to provide system testing services for your business.


This publication is for informational purposes only, and nothing contained in it should be considered legal advice. We expressly disclaim any warranty or responsibility for damages arising out of this information and encourage you to consult with legal counsel regarding your specific needs. We do not undertake any duty to update previously posted materials.