AntiPattern Problem A Boat Anchor is a piece of software or hardware that serves no useful purpose on the current project. Often, the Boat Anchor is a costly acquisition, which makes the purchase even more ironic. The reasons for acquiring a Boat Anchor are usually compelling at the time. For...

Background When Michael Akroyd presented the Gypsy AntiPattern at Object World West in 1996, he likened the transient appearance and then discrete vanishing of the gypsy class to a "Gypsy Wagon" that is there one day and gone the next. As we studied Akroyd's model, we wanted to convey more...

Background Functional Decomposition is good in a procedural programming environment. It's even useful for understanding the modular nature of a larger-scale application. Unfortunately, it doesn't translate directly into a class hierarchy, and this is where the problem begins. In defining this AntiPattern, the authors started with Michael Akroyd's original thoughts...

AntiPattern Problem Object-oriented analysis and design (OOA&D) models are often presented without clarifying the viewpoint represented by the model. By default, OOA&D models denote an implementation viewpoint that is potentially the least useful. Mixed viewpoints don't allow the fundamental separation of interfaces from implementation details, which are one of the...

Background In a data-mining expedition, we began looking for insight into developing a standard interface for a particular kind of system. The system we were mining was very similar to those we hoped would eventually support the standard we were working on. It was also a research-originated system and highly...

AntiPattern Problem Technology is changing so rapidly that developers have trouble keeping up with the current versions of software and finding combinations of product releases that work together. Given that every commercial product line evolves through new product releases, the situation has become increasingly difficult for developers to cope with....

Background Do you remember the original black-and-white movie The Blob? Perhaps you saw only the recent remake. In either case, the story line was almost the same: A drip-sized, jellylike alien life form from outer space somehow makes it to Earth. Whenever the jelly thing eats (usually unsuspecting earthlings), it...

Good software structure is essential for system extension and maintenance. Software development is a chaotic activity, therefore the implemented structure of systems tends to stray from the planned structure as determined by architecture, analysis, and design. Software refactoring is an effective approach for improving software structure. The resulting structure does not have to resemble the original planned structure. The structure changes because programmers learn constraints and approaches that alter the context of the coded solutions. When used properly, refactoring is a natural activity in the programming process.