Structured knowledge engineering: a Yourdon-based approach to the analysis and design of KBS

The tasks of analysing and designing knowledge-based systems (KBS) are put into a structured framework. In order to do this, a structured lifecycle for knowledge-based systems is introduced, as well as some tools that allow both the taking of a structured approach and the production of appropriate structured models of the knowledge domain. The authors look first at the process of KBS design to compare and contrast one of the most commonly used design methods, i.e. prototyping, with a structured design method. Making use of terminology introduced by Yourdon (1989) to characterise system projects, the author shows how the adoption of the more formal structured approach need not lead to any loss of the `freshness´ that is claimed as the characteristic of a prototyping approach. The various stages of analysis and design are analysed in order to introduce the tools needed to construct the structured models of the knowledge-based system. A very simple example is used to illustrate the ideas expressed