A crystal model of knowledge based application design

A methodology is described for all phases of the development of knowledge-based applications. This approach is based on the use of a performance system as a formal language throughput the project for defining the product specifications, implementing the functionalities, and testing them. All project aspects are defined in a knowledge-base format and then replaced when needed by the corresponding module written in the appropriate conventional language. The relation between this crystal model of expert system growth and the emerging iterating software engineering approaches, such as the Boehm´s Spiral model, is discussed. Requirements for such a formal language are investigated