A requirement management database system for product definition

This paper presents a database system developed to provide a computerized environment for requirement management during the product definition phase. The scope of this database system is to facilitate and demonstrate a methodology for product definition by recognizing and adopting functional requirement patterns from previous product designs so as to address a broad spectrum of domain-specific customer requirements and organize requirement information for product specifications. The database system improves the product definition process during design and redesign efforts by integrating customer and design information all together and by reusing this information. A prototype requirement management database system is implemented on a PC platform using Microsoft Access. This research is partially supported by Computer Products Asia-Pacific Ltd. (Power Conversion, Hong Kong) under grant number CPI 95/96.EG01, the HKUST Research Infrastructure Grant (RI 93/94 EG08), and Hong Kong Research Grant Council (HKUST 797/96E). development processes, they will increasingly demand various types of automated requirement management capabilities (Fiksel and Hayes-Roth, 1993). As a result, it is imperative to explore requirement management methodologies and develop computer tools to support requirement management automation. Towards this end, this paper presents a database system developed to provide a computerized environment for requirement management during the product definition phase, namely the requirement management database (RMDB) system. The scope of this database system is to facilitate and demonstrate a methodology for product definition by recognizing functional requirement (FR) patterns, noted as the PDFR methodology. The PDFR methodology adopts FR patterns from previous product designs to address a broad spectrum of domain-specific customer requirements and to organize requirement information for design specifications. The RMDB system is an implementation of the PDFR methodology to improve the product definition process during design and redesign efforts. The prototype RMBD system is implemented on a PC platform using Microsoft Access. In the next section, the background research leading to the PDFR methodology is presented upon which the requirement management database system is based. In Section 3, the system design issues involved in the development of the RMDB system are described, along with an existing database technologies review. The software selection and the RMDB system implementation are also discussed in Section 3. In Section 4, an example of product definition in designing power supply products is presented with a focus on the usage of the RMDB system. In Section 5, a plan for future work is presented and finally in Section 6 the paper is concluded. 2. Requirement management methodology Approaches to defining product specifications by capturing, analyzing, understanding, and projecting customer needs, sometimes called the Voice of the Customer (VoC), have received a significant amount of interest from both academia and practitioners in recent years (Fung and Popplewell, 1995; Fiksel and Hayes-Roth, 1993). A method used for transforming the VoC to product specifications is developed by Ofuji et al. (Shoji et al., 1993), in which semantics methods, such as the KJ method (affinity diagram) and MPM (multipickup method), are applied as the basis for discovering underlying facts from affective language. Kano et al. (1984) develop systematics to categorize customer needs for product definition. Towards this end, marketing researchers emphasize customer profiling by applying regression analysis to compare customer characteristics to determine their overall rankings in contribution towards profitability (Jenkins, 1995). Marketing research techniques include focus groups, one-on-one interviews, and similarity-dissimilarity attribute rankings (Griffin and Hauser, 1992). While these types of activities are helpful for discovering the VoC, it is difficult for them to obtain design information because marketers do not know what engineers need to know. They have shortcomings in facilitating the synchronization of marketing and engineering to develop product definitions coherently. In the engineering community, total design (Pugh, 1991) points out the importance of understanding and interpreting market information and encapsulating these in a comprehensive and thorough product design specification. Quality function deployment (QFD) (Clausing, 1994) joins both marketing and engineering efforts using a very basic tool of the matrix, namely the house of quality (HoQ). While QFD excels in converting customer information to design requirements, it is limited as a means of actually discovering the VoC (Hauge and Stauffer, 1993). To empower QFD with marketing aspects, Fung and Popplewell (1995) propose to pre-process the VoC prior to its being entered as customer attributes into the HoQ. In pre-processing, they adopted an affinity diagram (KJ method) to categorize and the analytic hierarchy process (AHP) to prioritize the customer requirements. Fukuda and Matsuura (1993) also propose to prioritize the customer's requirements by AHP for concurrent design. In summary, most approaches assume product development starts from a clean sheet of paper. In practice, however, most new products evolve from existing products. There is little attention paid to evolutionary product design in terms of product definition. Figure 1 The elaboration/refinement process of product definition