Object Mentor Blog: Aiming High: Good Architecture

Aiming High: Good Architecture

Tim Ottinger — Fri, 12 Jan 2007 10:46:34 +0000

Being perhaps more terse than precise, I provided this as a response to “What is a good Architecture”:

I would say that a good architecture is one in which a solution can be built, tested, and deployed, and within which all points of maintenance are singular and well-placed.

Now it’s nothing new, and nothing earth-shatteringly well said maybe, but I think it’s the first time I’ve successfully managed to express what I want.

Put even more vaguely and more tersly, I could say “it works and I can continue working in it”, but that actually says less than I want.

"Aiming High: Good Architecture" by Tim

Wed, 31 Jan 2007 13:44:04 +0000

I have been thinking about that a lot. We’re crafting a new course in professional OO development specifically for people working in a Java environment with legacy code. It has forced me to revisit all the Object Mentor design principles and I’ve realized that the “unique and well-placed” mantra seems to permeate them all, though not overtly.

The single responsibility principle is about both having unique points of maintenance, and placing them well.

The Open/Closed principle is likewise about placing changes well-placed in the hierarchy. It is more, perhaps, because it recommends abstraction and applies “well-placed” to the inheritance tree.

The Dependency Inversion Principle is again about having abstractions well-placed to manage dependency.

The Liskov Substitutability Principle is about keeping functionality well placed in an inheritance hierarchy, so that nothing is placed in the base that doesn’t belong, and no code that deals with the lowest implementor is misplaced in the top-level.

It goes on and on.

Also, there is an interesting Michael Feathers blog about things being well-placed (rather, knowing where to find them) that surfaced at this opportune junction.

Well, it’s on my mind all the time these days, along with the naming principles I’m rabidly revamping.

Thanks for the good words, Stan.

"Aiming High: Good Architecture" by Stan

Wed, 31 Jan 2007 09:46:51 +0000

I copied your response out of that discussion group when I saw it go by. I was just thinking that nobody else was really answering the question and trying to formulate something along those lines, but you did a much better job. Thanks!