Showing papers by "Barry O'Sullivan published in 1998"

A Constraint-Based Approach to Supporting Conceptual Design

Abstract: It is generally accepted that conceptual design is one of the most critical phases of the product development process. However, few systems exist which provide support to designers working in this stage of the product development process. In this paper, a constraint-based approach to supporting conceptual design is presented. This approach is based on a combination of constraint-based reasoning and design science. The approach described in this paper uses function-means trees to describe how function in design can be provided. Functions can be provided by either a principle, defined by a set of secondary functions, or an entity. An entity, in this context, is a tangible object represented as a frame in a constraint programming language. These frames are the building blocks from which a frame-based constraint network is built. This constraint network represents a class of schemes for the artifact being developed. Designers describe the product being designed in terms of function, required properties and criteria against which the final scheme will be evaluated. A constraint-based conceptual design assistant is being developed which assists a designer in developing schemes for an artifact being developed from an initial statement of function. This conceptual design assistant contains a database of function-means trees, a database of design entities and a set of libraries of DFX guidelines. Constraint-based reasoning is used to assist designers in developing concepts which are consistent with the various restrictions on the scheme being developed. These restrictions define the functionality of the artifact, the properties of the entities from which the artifact is configured and the technical limitations of the environment in which the artifact will be developed. Designers are informed of any inconsistencies in their decisions as well as any possible improvements which can be made to the scheme under consideration.

Supporting the design of product families through constraint-based reasoning

Abstract: A product family can be regarded as a collection of products which are similar - similarity being defined from a number of perspectives. For example, a collection of products may be regarded as a product family if they provide the same overall function, they have similar properties or they are built from the same parts. The objective of this paper is to demonstrate that constraint based reasoning offers a promising basis for the development of support tools for designers concerned with the design of product families. A constraint-based design environment is currently being developed which assists a designer in designing alternative product structures from an initial statement of required functional and physical properties. Each product structure can be regarded as an intentional specification of a product family - each member of which provides the same functionality and are physically similar in structure. In this paper it is demonstrated how a constraint-based model of a product family can handle the complexity of product family design. In addition, this paper discusses how a constraint-based model of a product family is readily extensible and facilitates the specification of new product families