以行動電話為例探討灰色田口方法於產品美感品質最佳化設計之研究

Optimizing Aesthetic Quality of Product Design by the Grey-based Taguchi Method: A Mobile Phone Case Study

產品造形所誘發的美感品質已成為影響消費者產品購買決策的重要因素之一。在過去相關消費者美感偏好的研究中，大多以單一向度指標，探討美感品質的改善，忽略了消費者產品造形美感的判斷是具備了多重品質的特性。同時，有關消費者之間品質評價的變異也未加以考量。為了達到美感品質最佳化與穩健設計之目標，研究以多品質之觀點，應用田口方法進行美感品質的最佳化；藉由灰色理論之灰色灰關聯分析解決多品質特性最佳化參數組合的衝突性問題，以灰關聯度為產品多品質特性的整體績效指標，再藉由田口最佳參數設計決定多品質特性之最佳因子水準組合。研究以「行動電話」為例，透過專家焦點小組與模糊層級分析法，求得美感準則項目與權重，再應用灰色田口方法推論美感多品質之最佳化造形參數組合，藉由驗證結果證明了多品質最佳化設計能達到整體美感績效的最大化與品質最小變異的目標，證明此模式應用在產品美感品質改善的可行性與有效性。

Aesthetic feeling elicited by the form of a product has been a critical determinant of its purchase by consumers. Previous studies on product aesthetics focused on how to improve aesthetics quality using a single criterion for evaluation. However, the multidimensional nature of aesthetic experience has made the optimization of aesthetic quality a multiple criteria decision-making problem. Hence, previous studies have neglected the difference in consumers' assessment of aesthetic quality. In this paper, a robust design approach combining grey relational analysis and Taguchi method is employed to maximize aesthetic quality taking into consideration multiple criteria for improving aesthetic quality as well as individual variation in aesthetic assessment. In this approach, grey relational analysis developed from the grey system theory is adopted to derive the overall performance index for multiple criteria and to solve the conflict of multi-response quality characteristic problems. A grey relational grade obtained from the grey relational analysis is used as the performance index in Taguchi method. Then, the parameter design proposed by Taguchi method is employed to determine the optimized design. The case study of a mobile phone is presented to illustrate and verify the feasibility of this approach. First, focus group and fuzzy AHP were held by experts to determine the multiple criteria and their weights. The grey-based Taguchi method is then employed to find the optimal design parameter setting by analyzing the relationship between the form elements and the aesthetic quality performance. Experimental results confirm that the optimized design of multiple aesthetic criteria characteristics has a superior performance on maximizing the quality and minimizing the variation of overall performance. The aesthetic quality of product form can be improved effectively using this approach.