| Summary: | The highly competitive and rapidly changing global business environment requires
companies to deliver new products with better performance, lower cost, higher quality and shorter time-to-market. To develop a successful product, conceptualization of the product plays an extremely important role and, hence, deserves much more attention. In essence, this work views product concept development (PCD) as a strategic task that has a major impact on subsequent production related activities.
In PCD, design evolution and evaluation are of great importance to generate satisfactory design concepts. To facilitate the efficiency of PCD and, hence, shorten the
time-to-market, this work aims at establishing new approaches and methodologies to
address the decisive issues of design evolution and evaluation in product
conceptualization. In so doing, it is found that current practices and literature have not
adequately addressed the issue of design information reuse in conceptual design
evolution. Such difficulties as indexing, retrieval and modification of prior design
knowledge remain to be dealt with. On the other hand, a knowledge-based approach has
been recognized as a promising and logical alternative to support design evaluation.
However, it is well-known that knowledge acquisition is the most time-consuming
phase, and, therefore, the bottleneck in constructing a knowledge-based system (KBS).
There are two major omissions in existing work. First, the quantitative characteristics of
information and interrelationships between various knowledge elements, which are of
critical importance in constructing a KBS, have not been investigated. Second, an
integrated and easy-to-use knowledge acquisition process with a well-organized
knowledge representation scheme to facilitate rule generation needs to be explored.
Accordingly, a feature-based design evolution approach via case-based reasoning
(CBR) is proposed to facilitate the evolution process of concept generation. In this
approach, a feature relationship decomposition (FRD) procedure is postulated. The FRD
provides an indexing scheme of CBR for design reuse with more flexibility of case
retrieval. The performance of analytical hierarchy process (AHP) is enhanced with FRD
via reducing the lengthy calculations of pair-wise comparisons. To arm the proposed
design evolution approach with the capability of innovation, a TRIZ-enhanced
innovative adaptation procedure (IAP) is investigated. Additionally, a matrix
representation and mapping approach (MRM) is proposed to tackle the difficulty of
knowledge acquisition in constructing a KBS to support design evaluation. The MRM
approach establishes a systematic procedure to model the rule generation process
mathematically. It uses matrix representation and mapping techniques to represent the
knowledge attributes and reveal their interrelationships. It addresses the quantitative
characteristics of relationship strength between various knowledge elements using a
relationship estimation procedure. Three case studies on wood golf club design, hard
disk design, and diagnosing automotive systems are employed to verify the proposed
approaches, i.e. FRD, IAP, MRM, respectively.
The economic impact of this work is to enhance design efficiency in new product
development so as to reduce design time and hence cost by effectively making use of
historical design data. In this work, the proposed CBR-based design system has been
tested on tangible product design problems. Given the proposed benefits, the possibility
of extending the current work to a broader scope will merit further exploration.
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