The mental process of predicting the reasonable consequences of a change in the design of an artifact is an important step in the design process. This research addresses issues in developing a theory of design change. The premise is that the incremental changing of the geometric design of an artifact may be formally explained by logical and mathematical theories, similar to those in automated planning and simulation systems which are used in many fields. Topics being investigated are representation of designs, designer intentions, and constraints. A computational model of the deductive process of changing a design is being developed. The model uses frame laws and default constraints expressed in the modal quantificational logic Z. Other work includes exploring problems of automated deduction of facts in three dimensional geometry, consistency analysis, and developing a taxonomy of appropriate engineering design actions and intents.
