Programming WCF Services, 2nd Edition

Service-Orientation

If you examine the brief history of software engineering just outlined, you'll notice a pattern: every new methodology and technology incorporates the benefits of its preceding technology and improves on the deficiencies of the preceding technology. However, every new generation also introduces new challenges. Therefore, I say that modern software engineering is the ongoing refinement of the ever-increasing degrees of decoupling.

Put differently, coupling is bad, but coupling is unavoidable. An absolutely decoupled application would be useless, because it would add no value. Developers can only add value by coupling things together. Indeed, the very act of writing code is coupling one thing to another. The real question is how to wisely choose what to be coupled to. I believe there are two types of coupling, good and bad. Good coupling is business-level coupling. Developers add value by implementing a system use case or a feature, by coupling software functionality together. Bad coupling is anything to do with writing plumbing. What was wrong with .NET and COM was not the concept; it was the fact that developers could not rely on off-the-shelf plumbing and still had to write so much of it themselves. The real solution is not just off-the-shelf plumbing, but rather standard off-the-shelf plumbing. If the plumbing is standard, the boundary problem goes away, and applications can utilize ready-made plumbing. However, all technologies (.NET, Java, etc.) use the client ...