## 3 Materials and Methods
### Initial AHP-QFD Matrices
#### 3.2.3 New Personal Electronic Product Development Design  
The study by [PERSON] et al. [24], focused on the application of a combined AHP with the traditional QFD method in the development of new products, specifically in a new earphone development project in Figure 7. The limitations addressed by integrating AHP with QFD in the study were as follows: (1) lack of prioritization: traditional QFD does not prioritize customer requirements and (2) subjectivity: the weights assigned to customer requirements are based on subjective evaluations and depend on the consensus of a panel of experts. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & & \\ \hline CR1 & 9 & 9 & 9 & 1 & 3 & 1 & & & 1 & & & 4.94 \\ CR2 & 9 & 9 & 9 & 1 & 3 & & & & & 3 & & 4.91 \\ CR3 & & & & 9 & & & & & & & & 4.66 \\ CR4 & & 9 & 1 & & & 3 & & & 1 & 9 & & 4.96 \\ CR5 & 3 & 9 & & & 3 & 1 & & & & 1 & & 4.84 \\ CR6 & 3 & 3 & 3 & 3 & & & 9 & 9 & & & 3 & 4.43 \\ CR7 & & & 3 & & 9 & 3 & 9 & 9 & 9 & & 3 & 3 & 3.71 \\ CR8 & 3 & 3 & 3 & 1 & 9 & 3 & 1 & 9 & & 9 & & 4.87 \\ CR9 & 1 & 1 & 1 & & & 3 & 9 & 9 & 3 & & 3 & 3.82 \\ CR10 & & & & & 9 & 3 & & & 1 & 9 & & 4.98 \\ CR11 & & & & & & 3 & 9 & & & & 4.69 \\ CR12 & 1 & 1 & 9 & 1 & 9 & 9 & 1 & 3 & & 9 & 9 & & 5.00 \\ CR13 & & & & & 9 & 3 & 3 & 3 & & & & 3.54 \\ CR14 & & & & & 9 & 3 & 9 & & & 9 & & 3 & 5.00 \\ CR15 & & & & & & & 3 & 3 & 3 & 9 & 1 & 9 & 4.83 \\ CR16 & 9 & 9 & 9 & 9 & 9 & 1 & 1 & 9 & & 3 & & 9 & 5.00 \\ CR17 & 3 & 3 & 3 & 3 & 3 & 1 & 1 & 3 & & 9 & & 3.35 \\ TRs & & & & & & & & & & & & & \\ weight & & & & & & & & & & & & \\ \hline \hline \end{tabular}  
* The list of customer requirements associated with this AHP-QFD include: (CR1) keep cool, (CR2) cooling generator, (CR3) temperature display, (CR4) anti-shock, (CR5) external heat detector, (CR6) temperature display, (CR7) bag form, (CR8) trustworthy, (CR9) lightweight, (CR10) covering, (CR11) sufficient capacity, (CR12) safety, (CR13) easy to carry, (CR14) easy to clean, (CR15) suitable price, (CR16) quality material, and (CR17) other utilities.  
\end{table} 
Table 4: Original matrix from AHP-QFD of a controlled-temperature medicine bag design ([30]. The process begins with data collection through questionnaires, interviews, and observations to identify customer requirements. These requirements are then analyzed and prioritized using AHP, which provides a structured method for determining their importance. The prioritized needs are translated into technical specifications using the House of Quality matrix structure. Finally, a prototype is developed and tested to ensure it meets the specified requirements, ensuring that the product aligns with customer needs and preferences. The House of Quality matrix structure follows the same QFD structure as explained in Figure 1, but assigned a numeric value; strong (3), moderate (2), weak (1) excluded benchmarking section. The initial AHP-QFD data will be presented in the same way as in the previous two studies. The initial data for this case are shown in Table 5.  
Table 5 presents the AHP-QFD matrix for the development of new earphones. This matrix, resulting in higher accuracy than the commonly used scale point evaluations. For example, customer requirements like light weight (CR1) and hold position (CR2), which were both assigned a value of 5 in point scales and could not be differentiated, were given precise weights of 0.239 and 0.143, respectively, using AHP. The matrix identified key technical requirements such as material (FR1) and weight (FR8) with weights of 196 and 182, respectively, indicating their critical importance in the design process. While AHP helps to prioritize customer requirements more accurately than simple point scales, it still involves subjective pair-wise comparisons. This subjectivity means that the values assigned can vary based on the judgment of the decision-makers. Therefore, if accuracy is paramount, AHP is preferred despite its subjective nature.