Testing Basic Interview Questions : What Is Integration Testing Explain It with Example?

What Is Integration Testing Explain It with Example?

When individual software modules are merged and tested as a group than it is known as integration testing. Integration testing is sets between Unit Testing and System Testing.

Integration Testing Example

For example you have to test the keyboard of a computer than it is a unit testing, but when you have to combine the keyboard and mouse of a computer together to see its working or not than it is the integration testing. So it is prerequisite that for performing integration testing, a system must be unit tested before.

Black-box test case design tactics are the most typical during integration, although limited amount of testing of white box may be used to ensure description of major control paths. 

Why we need integration testing?

Integration testing is executed to establish whether the components interact with each other consort to the specification or not. Integration testing in large refers to joining all the components resulting in the complete system. It is further performed by the developer or the software Tester or by both. Example- checking that a Payroll system interacts as required with the Human Resource system.

Integration Testing Types

1) Top-Down Integration Testing: As the name suggests, this testing always starts at the top of the program hierarchy and travels towards its branches. This can be done in either depth-first or breadth-first.

2) Bottom-Up Integration Testing: This testing always starts at the lowest level in the program structure.

Techniques of integration testing 

1) Top-down testing approach
2) Bottom-up testing approach
3) Big-Bang testing approach
4) Sandwiched testing approach


At last we conclude that Integration testing focuses on testing multiple modules working together and this testing is one of the extensive exercises of the software testing in which particular software modules are merged and tested as a group. 


  1. Clear explanation guys... Good :)

  2. when Programs are base-lined,then corresponding programmers can interconnect a those programs to build a software,here programmers can check correctness of programs interconnection.

  3. If we have 4 apps, in one its 2, in 2nd its 3, in 3rd app, its 2*3 and in 4th, its 6....What testing it would be? Integration testing or System testing, please explain. I faced this question in interview and was dumbstruck.

  4. wheres the example?

  5. Nice and understanding

  6. if we take facebook as example then how to apply integeration testing?

  7. Can any share integration test cases of any application

  8. Very informative and helpful...thnx

  9. integration testiong on pen?????

  10. The goal of integration testing is to make sure a system consisting of a number of components will function according to specifications when all the components are put together. If that is the case, why spend time testing interfaces between interacting modules? Why not just put them all together and test the system as a whole? can anyone Give arguments both for and against with examples.