The most effective way to improve management is to focus on the 80/20 principle. This enables the input to have minimum cost so that any improvements can create the best effectiveness. In order to arrive at such an effective way for making improvements, we should classify the quality characteristics with an orientation toward the customer's requirements and demands, so as accurately to determine key quality characteristics. Many papers have focused on output with the view to quality improvement of products, so here we will not only use the Kano two-dimensional quality model to define the key quality characteristics from the customers' point of view but also define those qualities (such as hygiene) for customer dissatisfaction; the one-dimensional motivation for customer satisfaction; the attractive motivation for customers' loyalty; and the indifferent and reverse quality for reducing waste and cost. We propose a case study to prove our methodology and use Six-Sigma's DMAIC (Define, Measure, Analyse, Improve and Control) as a tool. Subsequently, we focus on customers' expected level before using products and satisfaction after using products to survey the satisfaction characteristics as well as to survey some manufacturers (by questionnaire) on the achieved level of each quality characteristic. We then develop the performance matrixes for both levels. Finally, we transform the index value with two-dimensional performance into one with one-dimensional performance through our algorithm, so to develop index values for whole satisfaction and whole arrived level. The Kano two-dimensional quality model was developed to define the should-be quality, the one-dimensional quality, attractive quality, indifferent quality and reverse quality that provide better information for the considered manufacturers to develop a strategy for improving quality. In addition, the manufacturers could effectively and quickly measure and analyse the product quality by evaluating and improving the model proposed in this paper, and developing such strategies to improve based on the quality type. Finally, we effectively improve the whole quality satisfaction of the product in order to create the higher added value of product quality for competitiveness.

Six Sigma; DMAIC; performance matrix for satisfaction; performance matrix for achieved level; Kano two-dimensional quality model