The System Integration Testing is a testing process that shakes down http://en.wikipedia.org/wiki/Source_code - source code developed and fixes any variance before proceeding to the next testing phase. To complete (or exit) SIT, there must be fewer variances than can be tolerated.

The system integration process mainly depends on

• a formal methodology that leads to an efficient integration testing plan, and
• a consistency checking mechanism that validates the module subsystem interfaces and intermodule interactions during all the changes of the integration testing process.