Go back to all articles

Integration Testing vs System Testing

Dec 27, 2019
8 min read

Integration vs system testing both focus on the relationship between the modules of the software. It’s common for novice testers and business owners to confuse the two, their objectives, or their role in the SDLC.

The two testing activities are considerably different, although both are highly important for the product’s flawless functionality. In this post, we’ll examine integration and system testing, define their objectives and advantages, compare both testing methods. 

Integration Testing Definition

Sit testing definition describes integration testing as a subset of software testing that is designed to combine all the modules of a system into a single subsystem and validate their functionality. Typically, it is seen as the following stage after unit testing.

When designing integration test cases, project teams normally have to onboard testers. The QA team will work closely with the development and design departments to help create the best development and maintenance practices.

The Objectives of Integration Testing

The main goal of integration testing is validating if modules and feedbacks can work together in a synchronized way, that there are no errors interface-wise. Another objective of the activity is to validate the system’s compliance with the requirements stated by the service-level agreement.

There are other goals integration testing helps project teams meet:

  • Get early acceptability feedback
    Thanks to integration testing, software subsystems are validated right after the development of integrations is complete. As a result, the development team will know if the functionality of every module is satisfactory as early on as possible.
  • Ensuring that the memory usage is correct
    Memory leaks are a common issue during interactions between classes and modules. While the scope of unit testing is to narrow to catch such defects, integration tests are a way to search for unwanted interactions between modules and learn how to avoid them — this way, the tech team can be confident there will be no memory leaks between modules after the release.
  • Expose the flaws of integrated subsystems
    Integration testing allows developers to test each subsystem individually, as well as together with other components, to increase the precision of assessment and highlight the smallest functionality flaws.
  • Reduce maintenance costs
    Integration testing provides the tech team a better understanding of every subsystem, its structure, and function. It improves the quality of collaboration within the team since newcomer developers can use integration testing logs as documentation and familiarize themselves with the system. As a result, having conducted integration testing comes in handy in maintenance, reducing the time and effort needed to pinpoint the root causes of bugs and keep the system afloat.

Advantages of Integration Testing in Software Development

Even if a single module is running like clockwork individually, high-quality system performance is not guaranteed until all the error-free performance of all components is not ensured. If there is an integration defect between subsystems, the entire product will be affected. That’s why missing out on integration testing is a no-go for tech project teams.

The advantages that integration testing offers tech teams are numerous. Here are the most prominent benefits if brings out in projects:

Helps detect bugs early on

Integration testing is one of the first stages of the software development life cycle. Thanks to its broad coverage, it manages to examine the entire system as a sum of its components much more efficiently than unit testing that only focuses on the individual performance of the application units. Integration testing is essential for detecting module interaction issues as early as possible and laying the groundwork for future activities — validation, system testing, and others.

Can be conducted as soon as relevant modules are available

A QA team can start integration testing as soon as there’s a complete integration. That’s why, similarly to unit testing, the activity can be performed continuously throughout the entire development cycle, bringing in feedback that will help developers as they work on new, more complicated subsystems.

Provides a systematic approach for assembling software systems

Integration testing logs help establish the best development practices teams can follow when working on future projects.

A wide range of approaches and techniques

Integration testing is flexible — there are multiple ways to approach it. Depending on the way teams prioritize development tasks, testers can choose a top-bottom, bottom-up, big bang, or a different way to approach integration testing. It’s easy to run sessions without having to compromise the productivity of developers or designers.

Helps uncover interfacing errors

Integration testing validates the way components communicate with APIs, third-party elements, and interfaces. Since the activity requires tight collaboration between testers, designers, and developers, it helps create better views and includes checking if the interface corresponds well to developers’ logic.

System Testing Definition

System testing is normally conducted after the QA team has fully completed integration testing. The difference between system testing and system integration testing lies in the fact that the first targets the relationships within the assemblages, the main aim of running system testing is to conduct a large-scale checkup of the app’s user experience in the production conditions.

System testing is typically compliant with system requirement specifications (SRS). These tests assess both the design and the build’s functionality, taking both functional and performance expectations into account.

The Objectives of System Testing

System testing is a software development life cycle stage that analyzes the system as a whole and checks its correspondence to business and functional standards. It gives testers a possibility to see how the app operates under conditions that are close to the actual production environment.

Here are the chief aims of system testing:

  • Cut the post-deployment troubleshooting effort
    Since the testing environment closely resembles the one in which the end user interacts with the product, the outcome of the test will be similar to real-life conditions. By running system tests, tech teams save time on addressing customer concerns seeing as most weak spots and potential exploits were accounted for during testing.
  • Check if the system meets the SLA
    System testing is needed to help stakeholders ensure that the product is functioning as envisioned. Conducting system tests helps everyone invested in the product keep tabs on its development and avoid miscommunications that result in discrepancies between the expectations and the actual product.
  • Validate the application’s architecture
    System testing helps ensure that all the elements of the product are well-decoupled and organized, features can work autonomously without jeopardizing each other, and there’s enough room for scalability.
  • Validate the application’s functionality on a production server
    Thanks to system testing, a software product owner will be able to find out if the app is error-free when deployed on a live app server. By emulating the characteristics of a production server, teams can accurately predict the app’s response and ensure bug-free deployment.

Advantages of System Testing in Software Development

Unlike unit testing, which is conducted from a developer’s point of view, system testing is executed from the end user’s perspective. Although it’s common to associate ST with multi-layered, complex cases, the scenarios testers choose for testing can be relatively straightforward — e-commerce store owners can ensure, for instance, if they can add a menu tab for a new item to the navigation bar.

This versatility and broad scope of system testing are its major, but not only advantages. Here are some other benefits of the activity:

  • Includes end-to-end scenarios
    System testing offers the project team a 360-degree of the system’s behavior — how the hardware, software, and server components interact with each other, how the database operates, if it is secure, etc. After completing the testing stage, you will have a clear idea of whether or not the product is deployment-ready, which areas require more attention.
  • Increases stakeholder’s confidence in the project’s functionality
    After system-testing the product, a company owner will have an idea of the problems users might face once the app is deployed and the ways for the tech team to deal with these risks. As such, end-to-end testing improves contingency planning and helps stakeholders ensure there will be no reputation and financial losses.
  • Uses a testing environment that closely resembles the production environment
    System testing comes closest to mimicking real-world conditions. No other testing activity gives such a clear representation of what actual user experience will feel like.
  • Comprises a wide range of testing subsets
    System testing has a wide range of subsets — load testing, usability testing, and many others. Each of these analyzes the product from a different perspective, offering insights on how scalable, dependable, easy to use, or secure the product is.

Difference Between System Testing and Integration Testing

Although system vs integration testing are similar processes that, at times, require similar skills and use shared tools, you shouldn’t think that these are interchangeable definitions. There’s a clear difference between integration and system testing that’s presented in the table below:

System Testing

Integration testing

Fully analyzes the system

Is focused on the integrations within a given assemblage

Is the third step in the SDLC

Is the second step of SDLC

Testing black-box practices are used more commonly

White-box techniques are mainly used

There are more than one testing type

Does not branch out by different testing subsets as much as it does by approaches

Requires a high level of familiarity of the system’s structure

Requires a general command of the development logic

Test cases are built to emulate real-world conditions

The environment is designed to simulate interactions between modules

Have a Project in Mind?​
We have been working on performance testing projects since 2008.
Drop us a line to find out what our team can do for you.
Get a quote You’ll hear back from our tech account manager in one day if not sooner


Integration and system testing are crucial for a successful software product release. The former is needed to check that each subsystem functions properly while sit definition is in the assessment of the entire software system, its functionality, usability, and performance.

Both system testing vs system integration testing require a professional team. To be confident in the functionality of your project and know that it’s fully assessed and validated, contact PFLB — a leading software testing agency. Our testers will run fast and efficient integration and performance tests using the best industry practices and high-level tools — Jira, Selenium, and others.

Take a look at our portfolio to see the projects our specialists worked on. Contact us to discuss your project in detail — we will be happy to consult your team.

Table of contents
Let us know about your needs
We can provide multiple performance testing services and a lot more than that if the situation needs a far more complex approach.
Get a quote You’ll hear back from our tech account manager in one day if not sooner

Related insights in blog articles

Explore what we’ve learned from these experiences
8 min read

Why Load Testing Is Essential for Ecommerce Businesses

why load testing is essential for ecommerce businesses preview
May 17, 2024

The success of 26 million online retailers depends on the page load time. It significantly impacts the profitability of online services and sales, as customers don’t want to wait over three seconds to make a purchase. To ensure the desired speed, load testing is widely applied. Common Ecommerce Problems That Can Be Solved with Load […]

8 min read

Everything You Should Know about Performance Testing of Microservices

everything you should know about testing microservices preview
May 2, 2024

About 85% of enterprise businesses use microservices. In this article, we will cover the primary specifics of microservices, explain why they need performance testing, and highlight how to make this process efficient. Microservices in a Few Words Microservices (or microservices architecture) refers to a methodology for developing and deploying applications. This approach separates an extensive […]

4 min read

PFLB is Now SOC2 Compliant

pflb is now soc2 compliant preview
Apr 24, 2024

The PFLB team is happy to share the good news. We have passed the SOC 2 compliance accreditation. It means we can assure our clients that our cooperation will be entirely secure. What Is SOC? Introduced by the American Institute of CPAs (AICPA), SOC, or Service Organization Control, is a cybersecurity series of reports made […]

11 min read

How Do Businesses Benefit from Frontend Performance Testing?

how do businesses benefit from frontend performance testing preview
Apr 15, 2024

Crucial bottlenecks are usually backend-related. That’s  why backend performance testing is generally regarded as a must. However, only 1% of companies perform frontend performance testing. They don’t consider that to achieve the best business results, one should combine the two types.  Let’s prove it. We will define their differences, emphasize the importance of conducting backend […]

  • Be the first one to know

    We’ll send you a monthly e-mail with all the useful insights that we will have found and analyzed