Understanding the Difference Between System Testing and System Integration Testing

Understanding the Difference Between System Testing and System Integration Testing

3 July 2024 Stephan Petzl Leave a comment QA

When preparing for a software quality assurance role, it’s crucial to understand various testing methodologies. Two commonly confused terms are System Testing and System Integration Testing (SIT). This article aims to clarify the differences between these testing types, providing practical examples to help you apply this knowledge effectively.

System Testing

System Testing is performed on a complete, integrated system to evaluate the system’s compliance with its specified requirements. This type of testing treats the environment as a black box, focusing on validating the publicly exposed interfaces of the platform. Essentially, it simulates the behavior of an end user without privileged access to internal systems.

Key characteristics of System Testing include:

  • Testing the entire system as a whole.
  • Validating end-to-end scenarios.
  • Ensuring the system meets its functional and non-functional requirements.

Practical Example

Consider an online shop (System A) that operates independently. System Testing for this shop would involve verifying if a user can successfully browse products, add items to the cart, and complete a purchase. This process ensures the system functions as intended from the user’s perspective.

System Integration Testing (SIT)

System Integration Testing, on the other hand, focuses on verifying the interactions between different systems or components within a system. SIT is typically performed after individual modules or subsystems have been tested separately. It ensures that these modules work together as expected when integrated.

Key characteristics of System Integration Testing include:

  • Testing interactions between integrated systems or components.
  • Simulating real-world scenarios where systems must communicate and collaborate.
  • Identifying integration issues before the system goes live.

Practical Example

Continuing with the online shop example, suppose the shop (System A) uses PayPal (System B) for payment processing. System Integration Testing would involve verifying that the shop can successfully communicate with PayPal to complete transactions. This includes scenarios where the shop sends payment requests and handles responses from PayPal, such as payment confirmations or errors.


Understanding the distinctions between System Testing and System Integration Testing is essential for effective software quality assurance. While System Testing focuses on the system’s overall functionality from an end-user perspective, SIT ensures that integrated components or systems interact seamlessly.

For a more in-depth understanding of these testing methodologies, you may refer to our Advanced Testing Techniques documentation.

Enhancing Testing with Repeato

As software systems become increasingly complex, leveraging the right tools can streamline testing processes. Repeato, a no-code test automation tool for iOS and Android, offers a robust solution for creating, running, and maintaining automated tests for your apps. With its AI-driven approach and computer vision capabilities, Repeato simplifies the process of ensuring your systems and integrations work flawlessly.

For more information on how Repeato can enhance your testing strategy, visit our Getting Started guide.

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