System Integration is an important part of the Systems Engineering Process. Despite the fact that a product is really created during the integration, much more attention is given to the System Design activities than to the Integration. In my opinion changing the point of view and putting the Integration first can provide some useful insight. So - let's Forward the Integration!
It can be instructive to remember that whether not everyone is Systems Designer, almost everyone is Systems Integrator & Tester. Any time somebody turns on his cellular phone he triggers rather complex chain of events of integrating the phone into the Cellular Network System-of-Systems. This integration may be successful and may be not. In the latter case the cellphone user tries to find a spot with better coverage, reset the phone or declare the phone faulty - surely the activities familiar to practitioners during Sustems Integration&Test Phase.
So let's cast the light on last stages of some product introduction to society. We build the product, test it in the lab (controlled environment), in the field (controlled conditions of use), convince some people to buy the product by means of clever marketing, sell them the product, provide some instruction and leave them to INTEGRATE the product in their everyday life. If the integration is successful in most cases, we declare the product a success and the users that did not integrate the product well we call dummies. If the integration was not successful, we cannot call all users dummies so we scrap the product or get sued.
A product success depends on the INTEGRATION success by untrained users so we try to build sofisticated, complicated but NOT COMPLEX products. Conclusion - we are afraid of integration of complex products to the complex environment (i.e. society) so we try to make the product LOOK simple. When the product is really complex (like power station), we try to limit its use to highly trained professionals - we call them operators because by training we've LOWERED their complexity to the level that makes them respond predictably to the predictable system behavior.
Now - what does it mean for Systems Engineering? I don't know - yet. May be the whole purpose of SE in our compex world had shifted from Product Design to Problem Solving to Changing the World by Integration of Technology into Society in particular and the Universe in general? May be not - I think of myself as a Complex Being and it means a Confused One.