Fuzzy systems based on component software

7 This paper describes hierarchical modeling of fuzzy logic concepts that has been used within the recently developed model of intelligent systems, called OBOA. The model is based on a multilevel, hierarchical, 9 general object-oriented approach. Current methods and software design and development tools for intelligent systems are usually di5cult to extend, and it is not easy to reuse their components in developing intelligent 11 systems. The OBOA model tries to reduce these de7ciencies. The model starts with a well-founded software engineering principle, making clear distinction between generic, low-level intelligent software components, 13 and domain-dependent, high-level components of an intelligent system. This paper concentrates on modeling and implementation of fuzzy logic concepts within the hierarchical levels of the OBOA model. The fuzzy 15 components described are extensible and adjustable. As an illustration of how these components are used in practice, a practical design example from the domain of medical diagnosis is shown. The paper also suggests 17 some steps towards future design of fuzzy components and tools for intelligent systems. c © 2003 Published by Elsevier Science B.V. 19