Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

An Object-Oriented Representation for Product and Design Processes



Ram D. Sriram, S Gorti, A Gupta, Gerard Kim, A Wong


We report on the development of a knowledge representation model, which is based on the SHARED object model reported in [33,34]. Our current model is implemented as a layered scheme, that incorporates both an evolving artifact and its associated design process. To represent artifacts as they evolve, we define objects recursively without a pre-defined granularity on this recursive decomposition. This eliminates the need for translations between levels of abstraction in the design process. The SHARED model extends traditional OOP in three ways: 1) by allowing explicit relationship classes with inheritance hierarchies, 2) by permitting constraints to be associated with objects and relationships, and 3) by comparing similar objects at three different levels (form, function and behavior). Five primitive objects define the design process: goal, plan, specification, decision and context. Goal objects achieve function, introduce constraints, introduce new artifacts or modify existing ones, and create subgoals. Plan objects order goals and link a product hierarchy to a process hierarchy. Specification context objecs describe the design context. Operators that are applied to design objects collectively form a representation of the design process for a given context. The representation is robust enough to effectively model four design paradigms (described in Reference [9]): top-down decomposition, step-wise refinement, bottom-up composition and constraint propogation. To demonstrate this, we represent the designs of two TV remote controllers in the SHARED architecture. The example reveals that certain aspects of the artifact knowledge are essentially context-independent and that this representation can be a foundation for robust knowledge-based systems in design.

Journal of CAD
Volume 30, No. 7


Design, design process, knowledge-base, object-oriented model, ontology, representation


Sriram, R. , Gorti, S. , Gupta, A. , Kim, G. and Wong, A. (1998), An Object-Oriented Representation for Product and Design Processes, Journal of CAD, [online], (Accessed July 20, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 30, 1998, Updated October 12, 2021