Escaping the software tar pit: model clashes and how to avoid them

• Authors: Barry Boehm
• Venue: ACM SIGSOFT Software Engineering Notes
• Year: 1999

"No scene from prehistory is quite so vivid as that of the mortal struggles of great beasts in the tar pits… Large system programming has over the past decade been such a tar pit, and many great and powerful beasts have thrashed violently in it…"Everyone seems to have been surprised by the stickiness of the problem, and it is hard to discern the nature of it. But we must try to understand it if we are to solve it."Fred Brooks, 1975Several recent books and reports have confirmed that the software tar pit is at least as hazardous today as it was in 1975. Our research into several classes of models used to guide software development (product models, process models, property models, success models), has convinced us that the concept of model clashes among these classes of models helps explain much of the stickiness of the software tar-pit problem.We have been developing and experimentally evolving an approach called MBASE -- Model-Based (System) Architecting and Software Engineering -- which helps identify and avoid software model clashes. Section 2 of this paper introduces the concept of model clashes, and provides examples of common clashes for each combination of product, process, property, and success model. Sections 3 and 4 introduce the MBASE approach for endowing a software project with a mutually supportive set of models, and illustrate the application of MBASE to an example corporate resource scheduling system. Section 5 summarizes the results of applying the MBASE approach to a family of small digital library projects. Section 6 presents conclusions to date.