Why Testing is Necessary

Testing is the process of product validation. Based on testing, the client decides if the software is ready or needs to be modified. The primary purpose of testing is to answer whether the implemented software features correspond to the required and expected ones.

Testing is necessary to reduce the amount of low-quality software, applications, and other web products on the market.

It would seem that testing is done to ensure that the user has a quality product. But this is only one side of the coin. Testing is crucial first and foremost to the business. Once a company brings to market a product that has bugs, is unstable, and is difficult to operate, the cost of fixing these bugs becomes significant. The bugs found by the user while running the software are much more expensive than fixing them during the testing phase.

Testing saves money and resources. It allows you to fix most problems before breaking the whole system to correct them. 

There are several types of software testing, and all of these types have their features and applications. Testing is carried out to determine the functionality, performance, security, and usability by monitoring the software operation in special artificially created situations. And the rules of creating these artificially created situations are, of course, different for different kinds of testing.

In this article, we’ll talk about everything that concerns Integration Testing.

Integration Testing and Its Strategies

As we’ve already mentioned, there are several types of testing, and they are applied in a specific order. Integration testing is an intermediate stage between unit testing and system testing.

Integration testing involves checking the interaction between the tested modules and the systems that comprise them. A software product usually consists of several software modules written by different coders. Faults can occur when software modules interact and exchange data between them. Other names for integration testing are “I & T” (integration and testing), “line testing,” and sometimes “thread testing.” 

There are several methods for applying integration testing:

Big Bang Method

The essence of this method is to test all components together. If the system is not extensive, this approach is fast and convenient. If the system is extensive, it is challenging to localize errors. Testers can skip elements if there are too many of them. Because all modules are tested simultaneously, high-risk critical modules are not isolated and are tested in priority order. Peripheral modules, which deal with user interfaces, are also not isolated and tested for priority.

From the above, we can conclude that the Big Bang approach is potentially fast but risky method of software testing.

Bottom-up method

With a bottom-up strategy, you test each module at lower levels with modules at higher levels until all modules are tested. Top-ranked modules cannot be integrated into the software until lower-order modules have been tested. In a bottom-up approach, QA testers can use a Driver that acts as a special “connector” between the lower-order and upper-order modules. If a certain module stops functioning, its error can be corrected immediately, thus not wasting time waiting for all modules’ development, unlike the Big Bang approach. The disadvantage of this methodology is the inability to implement a prototype early on.

Top-down method

This methodology implies testing according to the control flow of the software system. From the name, we can conclude that it is the opposite of the previous method. All the top modules are tested first, and only then you can start testing the lower ones. Similar to the bottom-up approach, this method also depends on invoking a particular logical operator with a short program code, which is used to receive input by the lower modules from the upper modules during system integration testing. In short, testers call this operator a Stub. Most lower-level modules are tested individually, and then tests are performed in the aggregate of the implemented modules.

The Top-down method makes it easy to find bugs in the system, checking necessary modules separately from minor modules.

Hybrid method

This testing method is also called the “sandwich” method. Using a hybrid strategy, testers combine bottom-up and top-down methods. This strategy uses both stubs and drivers. It is ideal for large projects that require extensive hours of work. 

Why You Need Integration Testing

You may need integration testing for the following reasons:

  1. The understanding and logic of each programmer developing a separate module may differ.
  2. The customer may change requirements directly during module development, interfering with system integration. 
  3. The interfaces of software modules may contain errors.
  4. The hardware interface may contain errors in the hardware interface.
  5. Incorrect exception handling.

Integration testing is a must-have if a team is working on a project where the customer is constantly changing requirements, and the code structure and logic are subject to adjustments.

Integration Testing Benefits

Integration testing has many advantages over others. For example, integration testing allows two or more software components to work together (in integration). The system under test covers a broader range of components in a single sprint, thanks to the techniques described above.

Simultaneous testing of different modules saves time and money. 

Integration testing can be performed at any stage of software development and testing. Furthermore, considering the modular flexibility of integrations, this type of testing can be used on large and small projects with a different focus.

Integration testing allows you to monitor modules’ relevance and compliance with requirements, to classify program code into modules. Focusing on user scenarios, you can test the most relevant breakdowns: business logic, data model, and boundary situations.

The daily practice of using integration testing allows customers to maximize the commercial value of their web products.

Software testing is an integral part of the software development lifecycle. No matter how you do testing: manually or automatically, early implementation will keep the final product from critical bugs and seemingly invisible interacting bugs. Testing keeps the problem out of the production environment and thus saves the project from breakdowns in advance and the customer from losing money and reputation.

About author:

Robyn McBride is a journalist, tech critic, author of articles about software, AI and design. She is interested in modern image processing, tech trends and digital technologies. Robyn also works as a proofreader at Computools.