Designing for change, a dynamic perspective

Abstract

Despite advances in software engineering and process methodologies over the past decades, not many IT projects seem particularly well adapted to today’s fast-paced world. Software developers must start to acknowledge change and even uncertainty as a given, rather than the exception that should be studiously avoided, and they must adapt their techniques accordingly. Some business domains have seen attempts to address this situation. Several workflow vendors, for instance, have been marketing change and end-user programmability as major assets of their products. But, in general, they have been strangely ignorant of (good) modern software engineering practices, and the results have not really lived up to the claims. But we may expect a revival on a grander scale: the ability to (re) define the business logic on the fly is becoming a crucial asset when businesses re-align their core processes around the Internet. The Internet is transforming the way we envision and design applications. While we could build yesterday’s simple Web applications with, let’s face it, primitive techniques, this is simply no longer true. High-volume databases, long-term transactions, interoperability, distributed objects, re-use, these are some of the technical issues that must be dealt with. But the real challenge will be to leverage all this technology: we must empower the user to set up, maintain and change his applications more easily. We need dynamic systems, where applications can be changed at run-time in a high-level way, preferably by end-users. Above all, we need appropriate architectural techniques. In this paper we explore the use of dynamic object models. It turns out that the basic concepts are fairly simple. As for the difficulties, we can borrow solutions from many disciplines in computer science. If we do it right, we can even make the system work for itself.