An Integration of Kano Model, QFD and Six Sigma to Present a New Description of DFSS

Abstract

Business competitiveness is no longer a choice but a matter of survival in global market place. For any company, the continuous and timely development of new products and services, which include creative features that are expected to satisfy customers, is essential to remain competitive. At present, the companies not only focus on customer satisfaction, but also want to please them that ultimately lead them towards loyalty in future. Therefore, in-depth and quick understanding of the dynamic needs of customers can be important in the development of products and markets through a short period of time. However, there have been numerous failures in product development efforts leading towards enormous waste of time and resources. One of the reasons for this is the lack of a structured and comprehensive process for product development that utilizes powerful models and methodologies, such as Kano model, QFD and modern QI methodologies as well as the principles of concurrent engineering including cross-functional teams and timely communication. As all these methodologies share the same goals of pursuing customer satisfaction thus their integration into a common model is possible and beneficial Kano model strengthens the modern QI methodologies such as Six Sigma or Lean Six Sigma approach and further enhances customers’ satisfaction level. Six Sigma is used to achieve high-levels of stability through reduction in process and product variation. This directs to an almost defect free level which is also the focus of DFSS (or DMADV) building quality upstream for existing products and new product development methods. This level is essential to the customer, but not necessarily economic. Therefore, it is important to understand the customer's needs and requirements of the target, and understanding about company's own capabilities and costs. In addition to integrating Kano model and QFD into Six Sigma, the proposed approach extends previous works on these models. This paper presents a new description of the DFSS structured approach including a simple way for calculating the degree of importance for customer requirements with the adoption of Kano factor (K).An integrated approach for DFSS is proposed for practitioners to strategically understand the VOC. It included the use of different powerful tools such as Kano model, QFD, Taguchi’s QLF, TRIZ, AHP, DOE, SIPOC and FMEA. All of these tools are relevant and have consensus in terms of solving customer problems to achieve customer satisfaction. They also complement each other and can be integrated together, within DFSS, to form a better methodology. Therefore, the integration of these tools for the DFSS method is considered to be possible and useful. This work extended the previous works regarding these tools, included new ideas and incorporated them in a new model. Kano model lies in the center of the framework as it forms a basis for a profound understanding of the customer needs. The DFSS methodology utilizes Deming’s PDCA cycle through the DMADV phases for Cl. Kano model strengthens DFSS and brings an intelligent approach to understand and prioritize customer requirements. In addition, a generic case study is used to demonstrate some of the steps in the proposed methodology about how it can be implemented.

Keywords: Kano model, QFD, QI, Six Sigma, VOC, DFSS, QLF, FMEA, CI, DMADV, SIPOC, Customer satisfaction, product development