System integration is defined in engineering as the process of bringing together the componentA component or module is a discrete portion of a tool that has a particular function. Components can be assembled in dif... More subsystems into one system (an aggregation of subsystems cooperating so that the system is able to deliver the overarching functionality) and ensuring that the subsystems function together as a system, and in information technology as the process of linking together different computing systems and software applications physically or functionally, to act as a coordinated whole.