Proway Learning Technologies

Integration testing
Integration testing is the second level of the software testing process comes after unit testing. In this testing, units or individual components of the software are tested in a group. The focus of the integration testing level is to expose defects at the time of interaction between integrated components or units.

Unit testing uses modules for testing purpose, and these modules are combined and tested in integration testing. The Software is developed with a number of software modules that are coded by different coders or programmers. The goal of integration testing is to check the correctness of communication among all the modules.

Reason Behind Integration Testing
Although all modules of software application already tested in unit testing, errors still exist due to the following reasons:

Each module is designed by individual software developer whose programming logic may differ from developers of other modules so; integration testing becomes essential to determine the working of software modules.
To check the interaction of software modules with the database whether it is an erroneous or not.
Requirements can be changed or enhanced at the time of module development. These new requirements may not be tested at the level of unit testing hence integration testing becomes mandatory.
Incompatibility between modules of software could create errors.
To test hardware's compatibility with software.
If exception handling is inadequate between modules, it can create bugs.