posted on 1992-01-01, 00:00authored byRajaram Ganeshan, Susan Finger, James Henry. Garrett, Carnegie Mellon University.Engineering Design Research Center.
Abstract: "This research outlines a design methodology for recording the intent behind decisions in a design process. The design problem isdescribed as a conjunction of design objectives, which are high level descriptions of the requirements that the design artifact must meet (functional, financial, constructability, maintainability, disposability etc.). We use a combination of informal text, first-order predicate logic and arithmetic constraints to express design objectives. Importance can be associated with objectives. In this design process, the objectives can be addressed in some order by focussing on a subset of them. Objectives are achieved by a process of refinement which may result in a set of alternative bindings for the design variables involved, or, in alternative decompositions for the objectives.Assumptions may be made in the generation of the alternatives. The alternatives are evaluated with respect to other objectives and one alternative is selected. The design is completed when the current set of objectives is satisfied. Thus, the designer does not manipulate the form of the artifact itself; rather, the designer manipulates the objectives and selects alternatives, thereby revealing the intent behind the decisions. We also describe a representation for the record of this design process. The record can be used to identify the objectives and assumptions responsible for design decisions and for identifying the objectives and assumptions affected when decisions are modified. Weare developing an interactive computer-based environment in the domain of residential and small office buildings to demonstrate this approach."