Current Date :June 15, 2024

Introduction to Integration Testing

In software development, you strive to make features that support the application’s logic. During integration testing, we try to determine how various parts are integrated in order to release an app with a well-thought-out reason and error-free performance. As the title implies, we look at how various pieces are integrated. 

What Is Integration Testing? 

Integration Testing is said to be a kind of testing in which software modules are conceptually integrated and tested together.

Multiple software modules developed by different programmers or testers make up a typical software project. This level of testing’s objective is to discover problems with how various software modules interact when combined.

The purpose of integration testing is to determine how well these modules communicate. The name “I & T” (Integration and Testing), “String Testing,” and sometimes “Thread Testing” is also used to define it.

Why Perform Integration Testing?

  • Defects in integrated segments are very hard to discover and correct. You can benefit from running integration tests in such circumstances.
  • You may recognize and correct errors at the very start of the development process with integration testing.
  • End-to-end tests are less efficient than this one.
  • You can use this test to determine system problems like faulty database schema and cache integration.
  • Reducing the likelihood of software failure is likely through integration testing.
  • By conducting this testing, you can find out what structural changes occur when users switch between modules.
  • Bugs can be reduced by addressing problems in Integrated modules.
  • The possibilities for testing are broader with integrated testing since it covers a wider range of modules.

Types Of Integration Testing 

There are two different types of integration testing

Incremental Integration Testing 

In incremental integration testing, two or more logically related modules are integrated. Until the testers have tested the complete system, each module will be added one at a time to the testing unit. This method allows you to test the system for flaws in a smaller unit at an early stage while it is still relatively easy to determine the problem. 

This kind of testing strives to provide developers with feedback straight away so they can address any errors. Without impacting the other modules, any bugs found during this testing can be fixed. Stubs (called programs)  and drivers (calling programs) are typically employed in this approach to configuring the transmission. Drivers and Stubs are similar programs that are employed for communication.

There are three approaches for carrying out this integration test.

  • Bottom-up Approach: In this approach, testing starts with the lowest-level architectural module. The testing control flow begins at the bottom and rises. When the top modules are in development, this approach will be employed. The missing module’s functionality will be fixed using this method by using the drivers. This method of testing and creating a product is effective and has a high success rate. Compared to other conventional testing methods, it is faster.
  • Top-down Approach: This method involves beginning testing from the architecture’s topmost module. From the top, the testing control flow decreases. The working modules that are missing will be restored by employing stubs as duplicate programs. As stubs, which are often easier to construct than drivers, are employed in this manner, it is comparatively easier than the bottom-up approach. Due to this method’s progressive nature, it is easy to determine interface errors.
  • Sandwich Approach: It incorporates top-down and bottom-up approaches. This method involves testing lower modules with higher modules while also testing higher modules against lower modules. By simultaneously testing the top and bottom modules, the mid-module is where we should be. Stubs and drivers are both employed in this approach.

Big Bang Integrational Testing 

Typically, this type of testing is done only after all the modules have been completed. Once all modules have been completed, they will be connected to make a single software system before testing is carried out. Smaller systems normally benefit from this type of testing. 

The biggest disadvantage here is that some of your resources will be idle as they must wait for all the modules to be created before beginning the testing process. This makes it expensive and time-consuming regarding that each module will be developed before even starting the integration testing.

Benefits Of Integration Testing 

Integration testing allows the splitting of code into blocks made up of multiple units, allowing for incremental software component testing before system assembly. It suggests that all systems will be appropriately adjusted regardless of when, how, or why they were initially developed. 

Since only functional and highly-performing builds should be allowed to move on to the next stages of testing, verification of software integrity is essential. Otherwise, it will be harder and also take longer to discover bugs.

The advantages of integration testing, are as follows:

  • Simultaneous testing of multiple modules is quite convenient, functional, and cost-effective. 
  • Integration tests can be conducted at any stage of the SDLC.
  • It is a game changer for a team working on projects with frequently changing requirements or logic that is being examined after development has begun.
  • Unlike other kinds of tests, integration tests can cover any amount of program code in a single sprint.

Also Read: Gap Analysis In QA


This article concentrates on integration testing and We hope, we’ve demonstrated all about it clearly in this post. Integration testing is an important part of the testing cycle because it makes it easier to discover defects when two or more modules are incorporated into the first step.

It helps in the detection of errors at an initial point, saving time and money. It helps to assure that the integrated modules function properly.

Need to implement integration testing? Think no more! TestUnity provides testing services on-demand, serves with projects of any scale, and is ready to start with a few days advance notice. Choose to team up with a QA services provider like TestUnity. Our team of testing experts specializes in QA and has years of experience implementing tests with different testing software. Get in touch with a TestUnity expert today.


Testunity is a SaaS-based technology platform driven by a vast community of testers & QAs spread around the world, powered by technology & testing experts to create the dedicated testing hub. Which is capable of providing almost all kind of testing services for almost all the platforms exists in software word.

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