Any system is made using multiple components or modules which includes hardware part as well as software part. Integration means the set of interactions between all these components. And to test the interaction between these modules and to test the interaction with other external systems is known as integration testing. Integration testing is one of the main type of the Software Testing. Integration testing technique begins when two components of the product are available and ends when all component interactions have been tested. The last round of integration including all component is known as final integration testing (FIT), it is also known as “System integration”.
Integration testing method is a type of testing as well as it is a phase of testing. As discussed prior, integration is a set of interaction, so all defined interactions between the components needs testing. The design and architecture can give the details of interactions inside system; but, user needs to have a detailed information and understating about how they work together, to test the interactions between one system and another system. This knowledge or information about interaction (or you can say, how the software or system or modules work together) is dependent on many modules and system. These different modules could have different ways of working when integrated or combined with other modules or systems. This creates complexity in procedures and in what should be done to realize this complexity, a phase in testing is dedicated to test these interactions, which results in evaluation of process, this occurring phase is called the integration testing phase.
As integration testing is targeted at testing the interactions between modules, this testing has a set of methods and techniques. This is same like White box testing technique, Black box testing technique and other Software testing types. We will discuss about these methods and techniques in the coming articles.