Design for mass customization by developing product family architecture

Mass customization, aiming at delivering an increasing product variety that best serves diverse customer needs while maintaining near mass production efficiency, has recently received mulch attention and popularity in industry and academia alike. It has been considered as the new battlefield of manufacturing enterprises. This thesis deals with mass customization from a product development perspective. A framework of design for mass customization (DFMC) by developing product family architecture (PFA) is presented. To deal with tradeoffs between diversity of customer requirements and reusability of design and process capabilities, DFMC advocates shifting product development from designing individual products to designing product families. In addition, DFMC aims at extending the traditional boundaries of product design to encompass a larger scope spanning from sales and marketing to distribution and services. As the core of DFMC, the concept of PFA is developed to assist different functional departments within a manufacturing enterprise to work together cohesively. A PFA describes variety and product families and performs as a generic product platform for product differentiation in which individual customer requirements, can. be satisfied through systematic decisions of developing product variants. The economic implication of this approach for marketing and engineering is to reduce design expense and enhance manufacturing efficiency by reusing product designs and process capabilities. Based on such a PFA, the DFMC framework provides a unifying integration platform for synchronizing market positioning, soliciting customer requirements, increasing reusability, and enhancing manufacturing scale of economy across the entire product realization process. The fundamental issues underlying a PFA involve multiple perspectives on variety and product families, function variety versus technical variety, modularity and commonality, class-memberships inherent in variety, and PFA composition. The thesis proposes to represent a PFA from three perspectives, namely the functional, behavioral and structural views, in each of which the functionality, technological feasibility and manufacturability are characterized, respectively. A PFA supports DFMC in the way of configuration design, and thus consists of fclur major elements, i.e., the product line taxonomy, building blocks, configuration rules, and the economic evaluation. In essence, PFA development resides with the appropriate formulation of building blocks with the synergetic consideration of the functional, behavioral and structural perspectives. A methodology for PFA development is detailed in the thesis to match customer requirements with a company's capabilities through systematic planning of functional diversity and engineering reusability in terms of building blocks and their configuration structures through modularity and commonality across the functional, behavioral and structural views. Several decision-making tools are elaborated to facilitate the PFA-based product development life-cycle for mass customization. To support concept evaluation in configuraton design for mass customization, a fuzzy ranking methodology is developed by employing the fuzzy preference relation to model the fuzziness in conceptual design evaluation. The ranking approach integrates both intangible and tangible criteria into the fuzzy preference model, where the information content measure and the fuzzy line segment are adopted in performance evaluation to streamline different measures of diverse design criteria into a common metric and to connect customer satisfaction to the technical capabilities of a design. To facilitate rapid estimation of product costs according to high level design features instead of detailed process planing information, a pragmatic approach is proposed by adopting the activity-based costing concept and based on the standard time estimation. While standard routings provide a basis for estimating time requirements based on historical data, an activity hierarchy is formulated and used to trace the underlying activities that drive costs and to identify cost-related de,sig,n features that enable rapid product costing. To enhance requirement management for product definition in DFMC, a variant approach to product definition by recognizing functional requirement patterns is developed. A prototype requirement management database system based on this variant approach is developed using Microsoft Access© so as to improve customer needs elicitation, product specification generatIon and management of customer and design information in product definition. From the perspective of variety management for mass customization productjon characterized by a large variety, the application of the PFA methodology is demonstrated through constructing a generic bill-of-material (BOM) structure for handling diverse product variants. An object-oriented programming language is developed to describe a generic BCIM structure as a result of understanding a well-developed PFA. The variability of each component in the generic BOM is defined through a set of attributes and attribute values. Each particular product variant specification can thus be generated as an instance of the generic BOM by specifying these attributes. A prototype BOM processing system is developed using KAPPA-PC[copyright symbol][copyright symbol] Recognizing the necessity to understand product families through developing commonality measurements, the component part commonality and the process commonality are distinguished to characterize different sources and consequences underlying product families. Accordingly, the component part index and the process commonality index are formulated by taking into account the average repetition per component part, product volume, quantity per operation, costs of component parts, process flexibility, lot sizing, and scheduling sequencing. The thesis also reports case studies conducted in an electronics company for power supply products to demonstrate the potential and the feasibility of the DFMC framework as well as the PFA methodology