## 7 Results and Discussions
The _mean_ and _sd_ of all performance metrics are shown in Table 4, while the _median_ and _IQR_ of both the performance metrics for all mUAQMSTP instances are shown in Table 5. Values that are more favorable are shown in bold in each of these tables. Looking at the _mean_ and _median_, respectively, in Tables 4 and 5, we observe that DENSEA outperforms NSGAII for all performance measures, for all mUAQMSTP instances. Here, for all the instances in Table 4, DENSEA achieve better _mean_ for HV and IGD at both the confidence levels of 0.4 and 0.9. However, it can be seen from Table 4 that NSGAII generates a better _sd_ for HV for three mUAQMSTP instances. However, DENSEA produces better a _sd_ for IGD for four mUAQMSTP instances at the confidence level 0.4. Similarly, when the confidence level is set to 0.9, NSGAII generates a superior _sd_ for HV for four instances, and DENSEA produces a better _sd_ for IGD for three instances. Similar, analysis can be performed considering the _IQR_ values in Table 5 at both the confidence levels 0.4 and 0.9. This suggests that NSGAII and DENSEA are more consistent, respectively, for the HV and IGD, which are generated corresponding to each of the 100 executions of the MOEAs. Figures 6 and 7 support the same hypothesis of Table 5 at the 0.4 and 0.9 confidence levels, respectively. In particular, these figures use letter-value (L-V) plots [40] to graphically explain the HV and IGD values that are related to Table 5. Specifically, the L-V plots in Figures 6 and 7 for the respective confidence levels 0.4 and 0.9, display the medians as the horizontal lines along with many quartiles. Here, it can be observed that DENSEA outperforms NSGAII in terms of HV and IGD, since DENSEA has superior median performance indicators for all the instances compared to NSGAII for both the confidence levels. Moreover, we have graphically elucidated Table 4 in terms of displaying the difference of the mean values of the 100 observations for HV and IGD generated for both NSGAII and DENSEA on the deterministic models of the four uncertain instances at two different confidence levels, 0.4 and 0.9. For this purpose, we have displayed Gardner-Altman plots (Gardner and Altman [41]) as depicted in Figures 8 and 9. In each of these plots the markers 'X' and 'Y' in the x-axis represent the vector of data points generated by the NSGAII and DENSEA, respectively. Considering all the HV values in Figure 8, it has been clearly observed that the mean corresponding to 'Y' is evidently greater than that of 'X' for both the confidence levels. Whereas, in Figure 9, the mean values of 'Y' are desirably less than that of 'X' for the IGD. Figure 6: L-V plots of two performance metrics: (**a**) \(HV\) and (**b**) \(IGD\) for the four mUAQMSTP instances with respect to Model (8) at confidence level 0.4. Figure 7: L-V plots of two performance metrics: (**a**) \(HV\) and (**b**) \(IGD\) for the four mUAQMSTP instances with respect to Model (8) at confidence level 0.9. \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{ \begin{tabular}{c} **Confance** \\ **Level** \\ \end{tabular}