## 5 Results and Discussion
### Empirical Evaluation of the System Performance  
Although the cross-validation of different combinations of training and validation rates was conducted in the case study, the system performance in the case company was further validated. To effectively understand users' perspectives on the proposed system in the NPPM process, a survey before and after system implementation was undertaken by the NPD team, with a total of nine participating staff with extensive experience of NPD in case companies. The demographic details of the nine staff are summarized in Table 4. The interviewees in this empirical investigation were selected from two product streams in the case company.  
For the questionnaire, the measurement items are shown in Table 5, while the measurement scales followed the 5-point Likert scale. The entire survey was split into two sections--before and after the implementation of the proposed system--while corresponding briefing sessions were provided before answering the questionnaires. Regarding the  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Shelf No.** & **Stream** & **Position** & **Years of Relevant Experience** \\ \hline
1 & A & General manager & 21 \\
2 & A & R\&D manager & 8 \\
3 & A & Product manager & 5 \\
4 & A & Product manager & 6 \\
5 & A & Product manager & 5 \\
6 & B & General manager & 25 \\
7 & B & Product manager & 19 \\
8 & B & R\&D manager & 23 \\
9 & B & Product manager & 21 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Demographic information of the interviewees.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Aspect** & **Parameters** & **HC2** & **New Case** \\ \hline  & RS—Hardware & 21 & 21 \\ \cline{2-3}  & RS—Software & 30 & 14 \\ \cline{2-3}  & RS—Structural Investigation & 25 & 21 \\ \cline{2-3}  & RS—Product Testing & 12 & 12 \\ \cline{2-3}  & RS—Research Coordinator & 6 & 6 \\ \cline{2-3} HR (man-day) & PS—Product Management & 12 & 12 \\ \cline{2-3}  & PS—Project Management & 6 & 6 \\ \cline{2-3}  & PS—Trial Production Run & 3 & 3 \\ \cline{2-3}  & PS—Product Testing & 21 & 21 \\ \cline{2-3}  & SS—Art & 3 & 3 \\ \cline{2-3}  & SS—Product Quality & 3 & 3 \\ \hline  & Design and Prototype & 30,000 & 30,000 \\ \cline{2-3} Budget (CNY) & \multicolumn{2}{c}{Mould Development} & 300,000 & 250,000 \\ \cline{2-3}  & Trial Run & 10,000 & 10,000 \\ \cline{2-3}  & Certificate Application & 45,000 & 45,000 \\ \hline \hline \end{tabular}
\end{table}
Table 3: _Cont._second questionnaire, an in-depth briefing session was performed to educate the staff on CBR and transfer learning.  
As shown in Table 6, the results of the survey were summarized, while the Mann-Whitney U test was applied to evaluate the difference in the median before and after system implementation. Because the number of interviewees was limited to the case company, the use of the Mann-Whitney U test could effectively measure differences without checking for normality. Thus, it was suitable for the small-scale empirical investigations in the case study. Under the 95% confidence interval, it was found that the improvements in ease of use and system security were statistically significant following system implementation. When the 90% confidence interval was considered, the compatibility and overall performance were significantly enhanced. Consequently, the overall feedback from the interviewees was positive for system implementation in this case study, where the use of the proposed system effectively revamped the existing NPPM in the NPD process.