Matias: Development and maintenance of a large but well-defined application

Abstract

Abstract This paper presents experiences from development, use, and maintenance of a large rule-based expert system known as Matias. The application contains knowledge about farming loans in Finland. Using this large application as a reference point, we will discuss project management, knowledge acquisition, knowledge base design, and maintenance of large knowledge-based systems (KBS). Based on the experiences gained during the development of Matias we would like to promote better planning in KBS projects, use of structured knowledge base design principles, and use of graphics in representing knowledge to the experts. One graphical representation technique, dependency graphs, is presented in this paper. Techniques presented in this paper are applicable to most application areas but are of most importance to developers of large applications. Building a large application sets high requirements for system design, knowledge transparency, and knowledge management facilities.