Case Knowledge Management Of Product Design Based On Design Cognition And Design Process

In the Knowledge Economy Era, knowledge is an important factor and resource for the enterprises to develop the independent intellectual property products and to improve the own core competence by effective knowledge acquisition, knowledge accumulation and knowledge use. Product design case knowledge plays a key role in the enterprises and can increase their intelligence assets though information technology, network technology and knowledge tools from the three aspects: quality, quantity, and connotation. From the design cognition and design process viewpoints of product design knowledge, knowledge management of product design case is studies in this dissertation. The key issues include knowledge representation of product design case, knowledge operation and knowledge evaluation of product design case, similarity knowledge acquisition of product design case based on partial problem descriptions, meta-cognition modeling of individual designer and product design methodology based on case knowledge management.The main content and contribution of this dissertation are as follows:1. The multi-element knowledge representation model of product design case based on ontology idea is presented to describe product design case. Machine knowledge and human knowledge are defined from the point of view of knowledge classification. The characteristics, origin and life cycle of product design knowledge are analyzed, and product design case knowledge and product case knowledge are distinguished in this section. The characteristics of product design case knowledge representation involve systematization, complexity and process-separability. Furthermore, product design case knowledge is formalized by Backus-Naur Form (BNF), and Structured-Semi structured-Unstructured (SSU) case knowledge storage model is built to match the case knowledge representation. Finally, the relationship of case knowledge description and case knowledge storage is discussed and analyzed, and knowledge granularity and knowledge hierarchy are introduced in detailed.2. Knowledge operation framework of product design case knowledge is provided and is composed of routine operation and knowledge management operation. Routine operation includes add operation, delete operation, modify operation, query operation based on two-double search mode of top-down and bottom-up and browse operation based on SSU stencil-plant and attribute dictionary. Knowledge operation includes redundancy checking, unique checking, consistency checking, validity checking and collision checking. Furthermore, the quality indices architecture of product design case knowledge is presented to guarantee the correct, complete, reasonable and effective reusing of case knowledge and the case knowledge item indices of the elementary index set is analyzed. Finally, the dynamic evaluation model of case knowledge'quality for product design is developed, and evaluation flow, evaluation approach, evaluation arithmetic and related key techniques are studied and discussed.3. With the using of knowledge-intensive domain knowledge, additional knowledge and explanation knowledge, the similarity transformation matrix for similarity measures is presented to handle the partial problem descriptions of product design, and the similarity knowledge repair model of based on consultation is provided to repair the incomplete case knowledge and to retrieve the similarity knowledge. The concrete consultation hierarchy consists of feathers level, method and weight level and semantics level, and consultation approach is introduced to help effective knowledge repair of product design case.4. Based on physical symbol system hypothesis (PSSH) and connectionism, a meta-cognition model of product designer is provided to elucidate the active monitoring and consequent regulation, which affects the formation of product design case knowledge. Meta-cognition process and cognition process in product design are identified, and factors and characteristics of meta-cognition model of product designer and the relationship of individual cognitive and meta-cognitive activities are analyzed. Individual cognitive differences and problem solving are studied and analyzed, and fourteen cognitive differences are provided In the process of product design.5. Combining case based reasoning (CBR) and knowledge management (KM), product design model based on case knowledge management is provided. The relationship between product design and case knowledge management is discussed, and the mainly characteristics of product design based on CKM are investigated. Then, design methodology, design mechanism, design approaches, and key techniques based on CKM are introduced, and knowledge management techniques are studied and utilized in product design system based on CKM, such as, knowledge evaluation, knowledge sharing, knowledge update and knowledge map. Finally, the seven design rules are provided to serve and support product design.