Evolutionary prototyping: techniques for structuring the iterative development of knowledge-based systems

A knowledge-based software project management system called Dr. Watson is being developed using the automated reasoning tool (ART) and Common Lisp on Symbolics workstations. Dr. Watson has evolved over 1-1/2 years from a simple prototype of two to three pages of ART code to a system composed of 26 files; the current system comprises a conceptual model of project management, algorithms, and reasoning processes for project planning and scheduling, consistency and completeness checking, knowledge-aggregation capabilities, and a direct-manipulation graphics interface. Dr. Watson´s evolution has been smooth and controlled because of the techniques used to structure both the prototype and the prototyping process. The authors discuss these techniques, the process model used to organize Dr. Watson´s evolution, and the lessons learned from the project