ou’ve committed a dangerous act by printing Grady Booch’s article “The Irrelevance of Architecture” (May/June 2007). Way too many people already feel that architecture is irrelevant, and they’ll be tempted to read the misleading title, skip the article, and forever use Booch as proof of their erroneous beliefs about architecture. Additionally, I should admonish Booch for the invalid assumptions and errors of omission his article propounded on the way to reaching an otherwise good conclusion—namely, that architecture is quite relevant. A better conclusion would have been that a proper systems architecture is vital, desires of the agile cowboy coding hackers notwithstanding. One always has an architecture. It might have been done explicitly; otherwise, it’s ultimately defined by whatever the developers came up with. It all depends on which end of the dog is wagging the other. And this is not some Big-Endian vs. Little-Endian religious dispute (see Danny Cohen’s article “On Holy Wars and a Plea for Peace” in the October 1981 issue of Computer). When it comes to dogs, the tail should be the thing wagged, just as a design should be dictated by an architecture. And architecture is relevant to the end users. Without starting with a proper systems architecture, the end result won’t serve users well. They might not care about the implementation details, but they do care that the interface and functionality suit their needs when delivered. Although Booch observes the generic relationship between architecture and implementation, he omits the details that let software-

oriented people persist in their delusion that software is the system and that software architecture is synonymous with systems architecture—and that they can consider their part of the system without regard for the whole. Software is but one component supporting a systems architecture. To optimize the entire