A Constraint-Based System for Product Design

Concurrent Engineering (CE) emphasizes the simultaneous consideration of downstream aspects of product design (e.g., production, maintenance, recycling, and disposal) at the design stage. Representing these considerations at the design stage is one of the principal problems of CE. This paper explores the use of constraint networks to modeling such information for effective use during the design process. A constraint- based system has been developed in which the functional requirements of a product and other concerns about its life cycle are modeled as con straints. The system includes an interactive user interface, a constraint management module for the propagation and checking of design deci sions, and a constraint pool which supports different types of constraints from multiple knowledge sources. This system is a core part of a larger design assistance tool which is capable of mapping design requirements to multiple design alternatives. Main elements of the constraint-based system are explained and a parametric design case study is provided to illustrate the performance of the system in a practical mechanical design problem. Advantages and limitations of using constraint networks for modeling design knowledge and future research directions are also briefly discussed.