## 3 The New Approach Framework
### Phase 2--Customer Requirements Modelling: Investigation of Market Demand  
In Phase 2, market demand is investigated to obtain the customer preference for products. Quality function deployment (QFD) is integrated with the Kano model to qualitatively and quantitatively analyze the relationship between customer requirements (CRs) and customer satisfaction (CS) [44; 45; 46; 47]. Satisfaction-customer requirements (S-CR) relationship functions proposed by [PERSON] et al. [48] were used in this phase. A customer survey is conducted among the target users with a Kano questionnaire to help the construction of S-CR relationship functions, which is renamed as a customer satisfaction-Fulfillment (CS-F) relationship function [49] in this research. Customer requirements of a product refer to the judging criteria in customer evaluation [50]. Marketing experts help to identify the CRs to be involved for the product. Then, an investigation is performed to classify the CRs into several types. Based on the investigation result, CS could be mathematically expressed by the fulfillment level of each CR and integrated into the optimization model. The ID of each CR is recorded. QFD is implemented to construct the house of quality (HOQ) [51], which is the main representation to show the relationships between ECs and CRs. A typical HOQ is shown in Figure 3.  
The strength of relationship has a discrete value scaled from 0 to 9, as shown in Figure 4.  
Figure 3: Typical house of quality (HOQ). The strength of the relationship between \(CR_{i}\) and \(EC_{j}\) is denoted by \(R_{ij}\), whereas \(R_{ij}\in\{0,1,2,\ldots,9\}\). An example of a HOQ can be written as shown in Table 1.  
Then, \(R_{ij}\) needs to be normalized by Equation (1):  
\[R^{\prime}_{ij}=\frac{R_{ij}}{\sum_{j}R_{ij}} \tag{1}\]  
(The fraction of the sum of the row in HOQ)  
Thus, the normalized HOQ [52; 53] can be written as shown in Table 2.  
Equation (2) is always true to validate the normalized HOQ:  
\[\sum_{j}R^{\prime}_{ij}=1\quad\forall i \tag{2}\]  
(The sum of each row is equal to 1)  
\(R^{\prime}_{ij}\) can be considered as the contribution of \(EC_{j}\) towards \(CR_{i}\). The overall score of \(EC_{j}\) depends on its scores. It will require a fractional contribution of each score to calculate the overall score of \(EC_{j}\). The fractional contribution of score \(m\) of \(EC_{j}\) for \(CR_{i}\) is denoted by \(FC_{ij,m}\). Equation (3) must be always true:  
\[\sum_{m}FC_{ij,m}=1\quad\forall i,j\quad for\;R^{\prime}_{ij}\geq 0 \tag{3}\]  
An example of \(FC_{ij,m}\) can be written in a matrix as shown in Table 3.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**CR**} & \multicolumn{1}{c}{**EC**} & \multicolumn{1}{c}{**A**} & \multicolumn{1}{c}{**B**} & \multicolumn{1}{c}{**C**} & \multicolumn{1}{c}{\(\cdots\)} \\ \hline
1 & \(R_{1A}\) & \(R_{1B}\) & \(R_{1C}\) & \(\cdots\) \\
2 & \(R_{2A}\) & \(R_{2B}\) & \(R_{2C}\) & \(\cdots\) \\
3 & \(R_{3A}\) & \(R_{3B}\) & \(R_{3C}\) & \(\cdots\) \\ \(\cdots\) & \(\cdots\) & \(\cdots\) & \(\cdots\) & \(\Table 3 shows that the contribution of \(EC_{A}\) towards \(CR_{1}\) is weighted 80% on score 1 and 20% on score 2, and the contribution of \(EC_{A}\) towards \(CR_{2}\) fully depends on score 2, i.e., score 1 of \(EC_{A}\) has no effect on the fulfillment of \(CR_{2}\). The normalized strength of relationship, \(R^{\prime}_{ij}\) is then modified to \(R^{\prime\prime}_{ij,m}\), which represents the contribution of score \(m\) of \(EC_{j}\) towards the \(CR_{i}\). \(R^{\prime\prime}_{ij,m}\) can be calculated by Equation (4):  
\[R^{\prime\prime}_{ij,m}=FC_{ij,m}*R^{\prime}_{ij} \tag{4}\]  
The modified normalized HOQ can be written as shown in Figure 4.0  
If \(EC_{j}\) has only one score, Equation (3) can be simplified to Equations (5)-(6):  
Figure 4.1  
Figure 4.2  
\(EC_{B}\) has only one score. Therefore, \(R^{\prime}_{1B,1}\) is equal to \(R^{\prime}_{1B}\), and \(R^{\prime}_{2B,1}\) is equal to \(R^{\prime}_{2B}\). The fulfillment level of \(CR_{i}\) is denoted by \(F_{i}\).