Li Pheng Khoo

Desktop virtual reality for maintenance training: an object oriented prototype system (V-REALISM)

Virtual reality (VR) provides an intuitive and immersive human-computer interface, which can be an efficient tool for maintenance training. In this paper, a low-cost VR application for maintenance training, which is an object oriented prototype desktop VR-enabled system for maintenance (V-REALISM), is presented. It has successfully integrated a novel disassembly sequence planning technique and evolutionary algorithms with virtual reality using the object oriented methodology. Details of the system architecture design and its implementation are presented. A case study on the maintenance of a centrifugal pump system in a virtual workshop environment was used to illustrate the performance of the V-REALISM. The result shows the potential of desktop VR to maintenance training in cost reduction.

A strategy for acquiring customer requirement patterns using laddering technique and ART2 neural network

With the increasing interest and emphasis on customer demands in new product development, customer requirements elicitation (CRE) and evaluation have secured a crucial position in the early stage of product conceptualization. As such, it is highly desired to have a systematic strategy for soliciting customer requirements effectively, and subsequently, analyzing customer orientations quantitatively. For this purpose, a customer-oriented approach has accordingly been proposed and investigated in this study. It concerns both breadth and depth perspectives of customer requirements acquisition as well as customer and marketing analysis. This prototype system comprises two interrelated components, namely, the CRE and the customer/marketing analysis (CMA) modules. The process starts from the voice of customers and ends with the identified opportunities from marketing analysis. In the prototype system, the laddering technique has been employed to enable CRE via the so-called customer attributes hierarchy (CAM). In addition, the adaptive resonance theory, particularly ART2, neural network has been applied as a toolkit for further customer and marketing analysis. A case study on wood golf club design is used to demonstrate and validate this approach. q 2003 Elsevier Science Ltd. All rights reserved.

Design concept evaluation in product development using rough sets and grey relation analysis

Design concept evaluation plays a critical role in the early phases of product development as it has significant impact on the downstream development processes as well as on the success of the product developed. Essentially, design concept evaluation is a complex multi-criteria decision-making process involving large amount of data and expert knowledge which are usually imprecise and subjective. Aiming to improve the effectiveness and objectivity of the design concept evaluation process, this paper proposes a novel method based on grey relation analysis and rough set theory. By integrating the strength of rough sets in handling vagueness and the merit of grey relation analysis in modeling multi-criteria decision-making, a rough number enabled grey relation analysis (called rough-grey analysis) is proposed to evaluate design concepts. The result of an example shows that the proposed rough-grey analysis has provided a novel alternative to perform design concept evaluation, in which the vague design information and expert knowledge can be modeled and analyzed more effectively and objectively.

A dominance-based rough set approach to Kansei Engineering in product development

Keen competitions in the global market have led product development to a more knowledge-intensive activity than ever, which requires not only tremendous expert knowledge but also effective analysis of design information. Kansei Engineering as a customer-oriented methodology for product development, often has to analyse imprecise design information inherent with nonlinearity and uncertainty. This paper proposes a systematic approach to Kansei Engineering based on the dominance-based rough set theory. Two novel concepts known as category score and partition quality have been developed and incorporated into the proposed approach. The new approach proposed is able to identify and analyse two types of inconsistencies caused by indiscernibility relations and dominance principles respectively. The result of an illustrative case study shows that the proposed approach can effectively extract Kansei knowledge from imprecise design information, and it can be easily integrated into an expert system for customer-oriented product development.

An object-oriented intelligent disassembly sequence planner for maintenance

This paper presents a prototype object-oriented intelligent disassembly sequence planner for maintenance. A novel disassembly representation scheme known as disassembly constraint graph (DCG) has been proposed and implemented as a prototype system in this work. Using the DCG, all the possible disassembly operations that are needed for the maintenance of certain components or subassemblies can be deduced. Subsequently, a sequence-based optimisation technique, genetic algorithms, is employed to generate near optimal disassembly sequence from all the feasible combination of these disassembly operations. Based on the DCG, an object-oriented intelligent disassembly sequence planner for maintenance has been developed. The prototype system comprises three modules each having a set of objects. Users are able to view the entire disassembly process in accordance to the near optimal sequence generated by the planner via a graphical user interface. Two case studies, which are used to illustrate the effectiveness of the planner, are presented.

PDCS-a product definition and customisation system for product concept development

In recent years, owing to the rapid changing customer needs and much shorter product life cycle than ever before, employing more efficient and flexible approaches for product concept development has become an imperative for a successful product. This work aims at establishing a novel product definition and customisation system (PDCS) for organisations to meet this demand in todays competitive and globalised business climate. A prototype PDCS is proposed, from a design knowledge-handling viewpoint, in this paper. It comprises two phases, namely, product definition using the laddering technique and a novel design knowledge hierarchy (DKH), and product customisation using an integrated methodology of conjoint analysis (CA) and Kohonen association (KA) techniques. Basically, this system is a method of making design decisions via customer involvement, i.e. a strategy for transferring customer preference into a specific product concept. A case study on wood golf club design has been used to illustrate and validate the PDCS. The details of the validation are discussed.

An investigation into affective design using sorting technique and Kohonen self-organising map

In this paper, a prototype system that focuses on affective design perspective for iterative product concept development is proposed and described. The prototype system, which emphasises the solicitation of affective attributes from customers, employs a sorting technique, i.e. picture sorts, for acquiring customers affective requirements and a hierarchical structure for representing designers formal elements to meet customers affective requirements in product conceptualisation. As hierarchical structure alone contains qualitative and uncertain inherence, a self-organised algorithm known as Kohonen self-organising map (SOM) neural network is employed to consolidate the relationship between affective requirements from customers and formal elements from designers so as to formulate a customer-oriented product concept. The performance of the prototype system is illustrated by using a case study on the design of a mobile hand phone.

A QFD-enabled product conceptualisation approach via design knowledge hierarchy and RCE neural network

In this paper, an approach that attempts to improve conventional quality function deployment (QFD) technique in terms of effective design knowledge handling in product concept development is proposed and described. For this purpose, a QFD-enabled product conceptualisation system was established. It consists of three cohesively interacting modules, namely, design knowledge elicitation module using laddering technique, design knowledge representation module using design knowledge hierarchy (DKH), and design knowledge organisation module using restricted Coulomb energy (RCE) neural network. A case study on wood golf club design was used to illustrate the performance of the proposed approach. From the case study, the prototype QFD-enabled product conceptualisation system has demonstrated its effectiveness in design knowledge acquisition, representation and organisation at an early stage of NPD. The details of the validation are discussed.

An investigation on a prototype customer-oriented information system for product concept development

Abstract In a competitive and globalised business environment, a company can never out-perform its competitors, if it depends solely on its products alone. As a result, customer needs become an important factor to consider in new product development. In this work, a customer-oriented information system (COIS) was investigated and employed to establish a closer link between product re-innovation and customer involvement in the context of product concept development. It is aimed at improving design efficiency through managing multilevel product information, and reducing time and cost. In order to expedite the implementation of such an information system, a so-called functional attributes hierarchy (FAH) was proposed and developed to elicit product concepts and relevant design specifications from both generic and specific viewpoints. The correlation between them in terms of individual customer requirements was also identified with the utilisation of the analytic hierarchy process (AHP) technique. In addition, an object-oriented technique that enables information stored in a relational database (RDB) to be accessed was developed. The development is aimed at eliminating the semantic gaps between the data model and engineering designs. A case study on wood golf club design was carried out to validate the bespoke COIS for product concept development.

A web-enhanced dynamic BOM-based available-to-promise system

Abstract This paper describes a Web-enhanced dynamic BOM-based available-to-promise (ATP) system, which provides manufacturing companies with the ability to support the decision made by production planners and managers. In the paper, a concept of dynamic BOM is proposed. Based on the concept, the ATP computation algorithm is modeled and described in detail. Subsequently, the development of a prototype system is introduced. The system scenarios, system structure, architecture and some implementation issues are also presented. With the advent of Internet technologies, the proposed Web-enhanced dynamic BOM-based ATP system is simple to use and user-friendly. It supports centric management and can easily integrate with other applications.