A model of function-based representations

Abstract

The need to model and to reason about design alternatives throughout the design process demands robust representation schemes of function, behavior, and structure. Function describes the physical effect imposed on an energy or material flow by a design entity without regard for the working principles or physical solutions used to accomplish this effect. Behaviors are the physical events associated with a physical artifact (or hypothesized concept) over time (or simulated time) as perceived by an observer. Structure, the most tangible concept, partitions an artifact into meaningful constituents such as features, Wirk elements, and interfaces in addition to the widely used assemblies and components. The focus of this work is on defining a model for function-based representations that can be used across various design methodologies and for a variety of design tasks throughout all stages of the design process. In particular, the mapping between function and structure is explored and, to a lesser extent, its impact on behavior is noted. Clearly, the issues of a function-based representation's composition and mappings directly impact certain computational synthesis methods that rely on (digitally) archived product design knowledge. Moreover, functions have already been related to not only form, but also information of user actions, performance parameters in the form of equations, and failure mode data. It is essential to understand the composition and mappings of functions and their relation to design activities because this information is part of the foundation for function-based methods, and consequently dictates the performance of those methods. Toward this end, the important findings of this work include a formalism for two aspects of function-based representations (composition and mappings), the supported design activities of the model for function-based representations, and examples of how computational design methods benefit from this formalism.

Design-by-analogy: experimental evaluation of a functional analogy search methodology for concept generation improvement

“…Another benefit of functional models is the ability to standardize, allowing for the archiving and retrieval of design knowledge, for which a number of systems have been developed (Szykman et al 1999(Szykman et al , 2000Bohm et al 2005Bohm et al , 2008. Computational design tools have been developed to use the design knowledge contained in these functional repositories for concept variant generation techniques (Terpenny and Mathew 2004;Potter et al 2003;Hölttä-Otto et al 2008;Van Wie et al 2005;Kurtoglu et al 2009).…”

The Repeatability of High Definition Design Structure Matrix (HDDSM) Models for Representing Product Architecture

“…Similar models for product representation have been created for change propagation [11], a design knowledge repository [12,13], and representations for automated design [14]. A key distinction of the HDDSM is the format and process through which it is created.…”

A language for functional interpretation of model based simulation

“…For example several grammars (described in [19]) are available to describe mechanical systems functionality (including lathe, truss, vehicle, gear). Others have proposed generic functions based on energy flows [20,17] for example "conduit", "generator". These low level functions do not assist in explaining the purpose at the system level or the consequences of failures, which is the aim of this work.…”