Software development has for a long time sought to reduce the amount of coupling between various components of the system. The goal was creating systems where parts could be replaced without requiring massive amounts of rework — or simply replacing the whole system.
Portals, which are necessarily at the heart of an ever-changing array of programs and solutions within the organization are especially vulnerable to coupling. It starts out simple at first: the special notice that one application needs, and before long your portal projects are caught behind the schedule of a dozen other applications — and a dozen different projects are waiting on your portal project to be revised before they can put changes into their products
No matter how careful you are, there will be some coupling to other systems that cannot be avoided. However, taking a stand against allowing your portal to become coupled to other systems can make it easier to continue to update and revise your portal.