A PERSPECTIVE OF GENERATIVE REUSE

This paper presents a perspective of generative reuse technologies as they have evolved over the last 15 years or so and a discussion of how generative reuse addresses some key reuse problems. Over that time pe riod, a number of different reuse strategies have been tried ranging f rom pure component reuse to pure generation. The record of success is mixed and the evidence is sketchy. Nevertheless, the paper will use so me known metric evidence plus anecdotal evidence, personal experience, and suggestive evidence to define some of the boundaries of the succe ss envelope. Fundamentally, the paper will make the argument that the first order term in the success equation of reuse is the amount of dom ain-specific content and the second order term is the specific technol ogy chosen in which to express that content. The overall payoff of any reuse system correlates well with the amount of content expressed in the domain specific elements. While not a silver bullet, technology is not without its contribution and the degree of payoff for any specifi c technology is sensitive to many factors. The paper will make the arg ument that the generative factors predominate over other technology fa ctors. By looking closely at several successful generation systems tha t are exemplars for classes of related systems, the paper will examine how those classes have solved problems associated with the more conve ntion reuse of concrete components expressed in conventional programmi ng languages. From this analysis, it will distill the key elements of generative success and provide an opinion of approximately where each class of generative system fits in the overall picture. The result is a guide to the generative reuse technologies that appear to work best today.