If two or more modules or programs integrated to achieve 
the functionality then we use integration test process.

Integration testing aims at checking the connectivity of  
different modules of the application/system.Generally stubs 
or drivers are used for testing.

HI

  Integration Testing is used to check the data validation
  between modules or to check the business flow between
  the modules.




  sun_ramprasad@yahoo.com

System integration system is to test the entire 
application, this includes the validation,
best example money transfer

Tested some module can be integrated,and test can be start.
It is depends on 2 criteria.
1.Data dependancy 2.Data transfer.

Three type of integration testing is
1.Big Bang 2.Top down 3.Bottom up.

 Integration testing begins after Unit testing is
complete.The main intention here to discover any
discrepancies between the  module interface when individual
modules are combined together and to verify if they
communicate ( data flow) with each other as intended. 

INTEGRATION TESTING:
Definition: A process of testing the connectivity or data
transfer between the couple of unit tested modules.
		THREE TYPES OF TESTING.
INCREMENTAL 	----	Top-Down and Bottom-Up

BIGBANG 		----	Bigbang

TOP-DOWN INCREMENTAL TESTING:	A process of integrating
modules one by one using top-down approach.
	
	Stubs (Top-down)	:	Temporary modules which are replacements
of the original components.

	Process		:	Start integrating the module from top to bottom
and then do testing.

	Phase of testing	:	After Unit Testing.

	Automation		:	No, not needed.

BOTTOM-UP INCREMENTAL TESTING:	A process of integrating
modules one by one using bottom-up approach.

	Drivers (Bottom-Up)	:	Temporary modules which are
replacements of the original components.

	Process			:	Start integrating the module from bottom to top
and then do testing.

	Phase of testing		:	After Unit Testing.

	Automation		:	No, not needed.


BIGBANG TESTING		:	A process of integrating all the modules
together at once.

	Process		:	Start integrating all modules together and do
testing.

	Phase of testing	:	After Unit Testing.

	Automation		:	No, not needed.