Software testing is a fundamental element of the software development cycle. Within that process, integration testing stands out as the most important. This technique tests modules or components to validate that they work with each other as intended. In the context of software systems and software engineering, system integration testing is a testing process that exercises a software system’s coexistence with others.
You can check out our guide to learn how to create a test plan and a test automation strategy. “Integration testing” may also be used to refer to end-to-end system testing, verifying from the user perspective that all parts of an integrated system work together as expected. This is often seen as an activity to be done just before release, but as Gerard Meszaros points out, it really should be done up front.
An Example of Integration Testing
John Terra lives in Nashua, New Hampshire and has been writing freelance since 1986. Besides his volume of work in the gaming industry, he has written articles for Inc.Magazine and Computer Shopper, as well as software reviews for ZDNet. The only way you can discover problems that show up in testing is by logging your test results. Everything should be documented, so developers can consult the results and see what went wrong. Tessy is designed especially for embedded software and handles every aspect of the test organization, including management, traceability, and requirements. Modules are separately evaluated before being integrated to form a system in this sort of testing.
The integration layer acts as a medium or interface between the data import and export. You must have basic knowledge of certain schema technologies for performing SIT at this layer. This approach is adopted only when integration testing has to be done at once. The program is constructed and tested in small segments, where errors are easier to isolate and correct.
The Complete Guide to Integration Testing
Various integration testing methods exist, such as risky-hardest, top-down, big-bang, and others. Integration testing is executed through a black box testing approach where the testers utilize the software interface to interact with it. In integration testing, the focus is not on the codes or how they work but on how they function, which is tested through the interface. Unit testing is done on modules or units of the project individually to make sure they function as they should. Integration testing is done on groups of these modules to make sure they work together and interact properly.
- Integration testing, on the other hand, involves seeing how the different parts of the software under development work together.
- While it is recommended to keep the provision and scope of extensive logging, it should only be adopted when required, as this may affect the performance of the testing process.
- Sandwich Testing is a strategy in which top level modules are tested with lower level modules at the same time lower modules are integrated with top modules and tested as a system.
- In this scenario, extensive or exhaustive logging comes into play, which helps detect and fix the cause of the failure by considering the software’s different components.
- If you provide software as a service (SaaS), incremental integration testing is the way to go.
So, this process is, in essence, a fusion of the bottom-up and top-down testing types. And once all modules are available, testers test them together to check their interfaces and data flows. If no errors are detected, the end user should be able to successfully complete their transaction.
Software Engineering Integration Testing
In this approach, it is difficult to know the root cause of the failure because of integrating everything at once. The second approach is workable but can lead to significant overhead, as stubs become increasingly complex. Usually while performing Integration Testing, ETVX (Entry Criteria, Task, Validation, and Exit Criteria) strategy is used.
In the bottom-up testing approach, test drivers are needed to simulate higher-level units, which may not be available during the initial phases. Integration testing helps expose any defects that can arise when these components are integrated and need to interact with each other through integration tests. SIT (System Integration Testing) verifies interactions between integrated components, while regression testing ensures that recent code changes don’t adversely affect existing functionalities. The problems or issues are discovered early, so a significant amount of time and effort can be saved as you do not have to fix those issues at the later development stages. The minimum viable product (MVP) is released only when the system integration testing is validated and passed.
However, interoperability testing is needed to show that the true user need can be achieved in an operational context. Both integration and interoperability testing are typically needed to verify and validate how well software system integration testing definition components and systems work together. System integration testing is a level of integration testing that verifies the interaction and communication between different subsystems or components of a complete system.
The best practice to avoid such a scenario is dedicating separate suites for integration testing and unit testing. In sandwich integration testing, the sub-modules are tested along with the upper-level modules, while the top-level modules are integrated with the sub-modules for testing purposes. This makes integration testing more efficient, cost-effective, and time-efficient. Incremental integration testing is an effective way to detect problems early in development.