An agile development methodology for knowledge-based systems including a Java framework for knowledge modeling and appropriate tool support

Abstract

The goal of this thesis is to help make the development of knowledge-based systems more efficient. For that purpose, it proposes a new, agile software and knowledge engineering methodology, called XP.K (eXtreme Programming of Knowledge-based systems). This methodology is based on the four values simplicity, community, feedback, and courage, and applies object-oriented Round-Trip Engineering to knowledge modeling.

The thesis is founded on the observation that for most knowledge-based systems, knowledge must necessarily be modeled evolutionary, in a close collaboration between domain experts and engineers. The author argues that existing "heavy-weight" development methodologies from objct-oriented Software Engineering and Knowledge Engineering are often inefficient, because they make changes in knowledge models too expensive. Furthermore, they provide little support for the transitions between knowledge, knowledge models, and the remaining executable system. The starting point of XP.K is the hypothesis that "lightweight" - or agile - development processes (such as Extreme Programming) are suitable for knowledge modeling, because they are optimized for projects with frequently changing requirements and models and rely on a minimum of modeling artifacts with smooth transitions between them.

XP.K applies the main principles of Extreme Programming to knowledge modeling. The development process relies heavily on communication. Domain experts and knowledge engineers collaborate in the definition of metamodels (ontologies) and knowledge is acquired and tested in pairs. Ontologies are implemented in the object-oriented language which is also used for the remaining modules of the system. Prototypes are produced rapidly and frequently exposed to automated tests and constraint checks. XP.K is supported by a comprehensive, ready-to-use framework for implementing knowledge-based systems in Java.