Projection-Based Knowledge Representation for Concurrent Engineering zyx Carsten Thomas zyxwvut * Daimler-Benz AG Alt-Moabit 96a 10559 Berlin, Germany thomas@dbresearch-berlin.de ABSTRACT This paper describes an integrative approach to repre- sent knowledge structures and entities in the concur- rent engineering enterprise. General types of knowl- edge are classified and presented in various perspec- tives and abstractions. A new concept of knowledge representation based on zyxwvutsrqp projections is introduced. It is demonstrated how the projection concept inte- grates various facets of CE. Conclusions discuss the benefits of the proposed representation scheme and discuss potential application scenarios. 1 INTRODUCTION Concurrent Engineering (CE) [l] paradigm has emerged in response to increased global competition in product design, deployment, and marketing. The main characteristic of CE is the integration of all development activities and as well as participating teams through the entire product life cycle. In a holistic perspective, CE is both an organizational and technological effort. In this paper, we focus on the technological aspect, namely, on the adequate knowl- edge representation to support the concurrent engi- neering process. In the existing CE systems, general purpose knowl- edge representation schemes such as semantic nets are used zyxwvutsrqpo [a]. However, these representations do not pro- vide efficient methods for knowledge acquisition and handling. In this paper, we introduce a new formal means of knowledge representation that overcomes the lim- itations of the current schemes by combining the strengths of both, general purpose and specialized representations. The new scheme is intended to (i) address the variety of knowledge aspects, (ii) help structure CE knowledge in a clear and concise man- +This research has been conducted while the first author was on a sabbatical at The IJniversity of Arizona, Department of Electrical and Computer Engineering. Jerzy W. Rozenblit Dept. of Electrical and Computer Engineering The University of Arizona Tucson, AZ 85721, U.S.A. jr@ece.arizona.edu ner , (iii) support maintaining knowledge consistency and avoiding knowledge redundancy. To achieve these goals, we propose to use an object-centered approach in combination with a new method for the differentiated access to the acquired knowledge. The new representation scheme is called Projection-Based Knowledge Representation. zyx 2 CONCURRENT ENGINEERING KNOWLEDGE This section characterizes knowledge facets that are predominant in CE. Structuring Engineering Knowledge In Concurrent Engineering processes, an overwhelm- ing amount and variety of knowledge is available and has to be used. To be represented, the knowledge used in the engineering processes has to be structured through an ordering scheme and a means to capture the interdependencies among the different character- istics of knowledge. We propose a fourfold structuring of the engineer- ing knowledge: zyxwv e A piece of knowledge belongs to one of three general types of knowledge: knowledge about an engineering domain, knowledge about the spe- cific product to be designed and produced, and knowledge about how to design and manufacture products. e A piece of knowledge serves a certain perspective of the design (e.g., it contains geometric, tempo- ral, or behavioral knowledge). 0 A piece of knowledge describes something on a certain level of zyxwvu abstraction. e A piece of knowledge has a certain maturity. In the following, we will review these characteristics in more detail. 0-7803-2559-1/95 $4.00 0 1995 IEEE 3863