An extended Kano model for deciding improvement priority of product attributes

Consumer satisfaction with product design is a critical factor to a product's success. To resolve the trade-offs dilemma in multiple-attribute optimization of consumer satisfaction, this paper presents how Kano model can be used to help companies or designers prioritize attributes and allocate resource in different competitive situation in the development of a new product design. According to the Kano model, attributes should be classified into different categories, must-be(M), one-dimensional(O), attractive(A), indifferent(I) and reversal qualities(R), depending on their ability to create consumer satisfaction or cause dissatisfaction. Considering the difference of consumer perception between subjective and physical quality attributes, in this study an extended Kano model comprising one additional quality types beyond the conventional Kano model, i.e. nominal-the-better (NB) and further distinguishing the reversal qualities(R) into four sub-types (-A, -O, -M and -NB), is proposed and discussed. While a formula combining a decision matrix with the Kano classification results was further proposed to infer the proper proportions which should be allocated to each attribute for improvement. For demonstrating the procedure of implementing this formula and the practicability of the proposed approach in product design, a mobile phone design improvement plan was developed and discussed.