隨著時代潮流與生活水準提高，生活中充斥著各式各樣的產品，使得設計師必需從消費者生活型態中，挖掘潛在的需求，並找出符合消費者需求之產品，而有效的設計與評估則是開發產品的重要關鍵。然而絕大部分方案評選行爲，往往僅憑設計者的經驗及刻板印象，進行難以控制且不精確的決策。若此階段造成決策上錯誤，將易導致產品開發成效不彰。其次，若設計階段對於構想來源無法明確得知，易造成黑箱作業，爲改善此缺點，有必要將設計階段予以明箱化。因此，本文以廚房用電話的設計爲例，利用AIDA法的展開與價值工程的分析，作爲造形構想發展的依據。當完成產品設計時，爲重新檢視新產品是否符合設計目標，研究將藉由模糊綜合評價法進行產品的擇優評估，以減少決選過程中產生的不確定性與模糊性。研究顯示，此模式之建立將有助於設計過程之理性化，降低評選失誤與提高評選決策效率，增加新產品開發成功機會。

With the progress of technology, environmental changes and the living standards are increasing, giving rise to diverse abundance of consumer products. Consumer product designers generate product paradigms by discovering and assessing the attributes of consumer necessities and demand. Appraisal and effective design are the keys of this development processes. However, most design estimation is fuzzy and there is a high level of uncertainty during this stage. Making any mistake at this stage could easily lead to improper product development in subsequent stages. Furthermore, latter stage designers may be unfamiliar with concept origins not only leading to inappropriate development but unlawful development. In order to improve this shortcoming, there must be a rational method for assessment and development. The objective of this paper is to develop a rational method for shaping the product. In this paper, the design process of a telephone is used as an example. First the AIDA (Analysis of Interconnected Decision Areas) and VE (Value Engineering) method is used to investigate the problem. Second, we construct a fuzzy synthetic evaluation model in attempt to reduce choice process uncertainty and in determination. The result shows that these models contribute to the rationality of the design process by not only reducing errors but also improving decision making efficiency.