Towards a pattern language for knowledge processing systems: expert systems

Existing knowledge processing systems, especially expert systems, do not always fit to a company's needs. This reduces the benefits of such a technology, or even completely prevents their usage. Therefore, an architectural guideline is needed to enable software engineers to design and implement custom knowledge processing systems. In this paper a first approach via a pattern language for knowledge processing systems, consisting of five patterns covering the basic components needed, is presented. The patterns were extracted from three different open source expert systems / rule engines. The applicability of the patterns is discussed by applying them on an example custom knowledge processing system project that shows how the pattern language supports the design and implementation.