# Smart Product Design Process through the Implementation of a Fuzzy Kano-AHP-DEMATEL-QFD Approach
## 3 Proposed methodology  
The above considerations were incorporated into a novel methodology (Figure 2), supporting the smart product design process:  
* Step 1: Identification of customer needs. These customer needs were identified through an evaluation of customer claims and recommendations, but also by the permanent contact with physicians.
* Step 2: The design department at the company analyzed the needs and proposed some design features/actions to fulfill customer expectations.
* Step 3: The fuzzy Kano survey was implemented to the physicians. This survey allowed the team to classify each need as must-be, one dimensional, and excitement. The relevance of this classification laid in identifying the influence that each need would have on customer satisfaction or dissatisfaction.
* Step 4: Implementation of AHP. With the implementation of AHP, the perceived weights of each need would be identified.
* Step 5: Implementation of DEMATEL. With the implementation of DEMATEL, the overall influence for each one of the design actions/features would be identified.
* Step 6: All the collected information was compiled in the QFD matrix. AHP and Kano influence values would be located next to its corresponding customer needs (rows). The columns would have the design actions/features and also its corresponding weight (calculated with DEMATEL).
* Step 7: The design team filled a survey to identify the relationship between each customer's needs and each design action.
* Step 8: Calculation of satisfaction influence for each design action, through the information in the QFD matrix.
* Step 9: Prioritization of design actions/features.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Author**} & \multicolumn{5}{c}{**Used Methods**} \\ \cline{2-6}  & **AHP** & **QFD** & **DEMATEL** & **Kano** & **Comments** \\ \hline [PERSON] et al. [30] & X & & & X & Determination of priorities of customer requirements. \\  & & & & & No relation to design actions. \\ \hline [PERSON] et al. [58] & X & X & & X & Integration with fuzzy logic. Determination of customer requirements. Prioritization of design actions. It can be improved with the integration of DEMATEL to consider the influence of the different actions on the others. \\ \hline [PERSON] and [PERSON] [59] & & X & X & Determination of design actions. It can be improved if integrated with Kano to have a better representation of the impact each action has on customer satisfaction. \\ \hline [PERSON] et al. [25] & X & X & & X & Must be integrated with DEMATEL and fuzzy logic to understand customer requirements effectively. \\ \hline [PERSON] and [PERSON] [24] & & & & X & Integration with fuzziness. A good prediction of customer satisfaction. \\ \hline Proposed model & X & X & X & X & Integration of fuzziness. Great ability to determine the satisfaction index associated with each customer requirement. Relationship between design actions and customer requirements. Use of AHP and DEMATEL to better understand customer needs and design actions impact. \\ \hline \hline \end{tabular}  
* AHP: Analytic Hierarchy Process; QFD: Quality Function Deployment; DEMATEL: Decision Making Trial and Evaluation Laboratory; TOPSIS: Technique for Order of Preference by Similarity to Ideal Solution.  
\end{table}
Table 1: _Cont._The concepts of the calculations behind each one of the integrated methodologies are explained below: