One of the fun parts of being a software architect is trying to figure out how to build whatever it is that you are supposed to build. It's even more fun when you look at the architecture for an entire enterprise, and have to make choices that integrate every complexity and account for every nuance of the portfolio, even if only long enough to get something in place before ripping something else out.
The advantage of buying a COTS product from a software vendor is that you get expertise at programming, and in a particular line of business, without having to hire, retain, and pay a staff of programmers. This ability to buy functionality was a major innovation in the entire software development process, and a boon to departments that no longer had to wait out a long, waterfall-based life cycle before they got applications to assist them in doing their jobs more effectively.
Fortunately we have Web services now. Many of the problems caused by silos of applications can be mitigated by applying the technologies developed for Web services. Platform differences can be overcome. Communication mechanisms can be established. Locations of services can be determined.
