What is the difference between System Integration Testing and Unit Testing?

Answer 1

Unit testing tests individual components. Such as, if you modified a program to behave in a specific way under a specific set of conditions, you would test that it does precisely that.

System Integration Testing tests a program within the entire system. For example, you would also test programs that run before and after this program to ensure that they were not negatively impacted by your change.

Answer 2

Unit Testing Vs System Testing

Answer 3

In Unit Testing, you test a component or part of a software application to see if it works correctly by itself. Many developers use a Unit Test Framework such as JUnit for Java (other languages have other framework) to accomplish this kind of testing. In Integration Testing, you test the combined components/parts of a software application to see if they function correctly together, as a whole. As such, integration testing is typically done after unit testing and is more common for distributed applications (tiered, client/server, internet applications).

Answer 4

System intergratation testing is the testing of the different entities that make up that system and how they communicate or interact with each other to provide the solution the system is crated to carry out
while unit testing is the testing of each unit in the system and how that unit works by itself if it functions properly

System intergratation testing example.

how does the computer components like motherboard, harddisk, proccesor, RAM interact inorder to eanble you retrive a document edit it and save it so as to edit it later.

system unit testing example,

does the processor work properly according to its desing specifications?

Answer 5

in unit testing, you test only one program or module
but system integration testing merely tests that 2 or more separate modules or programs or systems can work together as expected.

Answer 6

Just as the names suggest.

Unit testing attempts to check each part of the system is working correctly.
http://en.wikipedia.org/wiki/Unit_testing
System integration testing attempts to test the entire system as a working entity.
http://en.wikipedia.org/wiki/Integration_testing

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