## 4 Results and Discussion  
This section compares the conventional FMECA method and the developed ExJ-PSI model to demonstrate the effectiveness of the proposed model. However, a literature review shows that many MCDM methods were developed to improve the effectiveness of FMECA. However, most of them cannot handle complex systems [41]. Therefore, involving a large group of experts is necessary to solve the complex systems of FMECA. The developed ExJ-PSI model considers the parameters affecting the operational safety and cost features in actual industrial applications. The developed model allows a large number of experts in the analysis and considers different kinds of uncertainty in experts' judgments. [PERSON] and [PERSON] [42] stated that the average and median individual scores also perform better than the group consent method. Therefore, the final results of the FMECA of the boiler system by the proposed method, normalized median method, and conventional FMECA method are \begin{table}
\begin{tabular}{l l l l l l} \hline \hline \multicolumn{1}{c}{**Sub-Systems**} & \multicolumn{1}{c}{**Component**} & \multicolumn{1}{c}{**Overall CI of**} & \multicolumn{1}{c}{**Criticality Rank**} & \multicolumn{1}{c}{\begin{tabular}{c} **Overall CI of** \\ **Sub-System** \\ \end{tabular} } & \multicolumn{1}{c}{**Criticality Rank**} \\ \hline \multirow{6}{*}{\begin{tabular}{l} **Combustion and** \\ **Ignition System** \\ \end{tabular} } & \begin{tabular}{l} Furnace \\ \end{tabular} & 1.5559 & 22 & \multirow{6}{*}{13.7475} & \multirow{6}{*}{2} \\ \cline{2-2} \cline{4-5}  & Shell & 2.1224 & 19 & & \\ \cline{2-5}  & Header & 5.1139 & 6 & & \\ \cline{2-5}  & Intake vent/Air vent & 1.8910 & 21 & & \\ \cline{2-5}  & Combustion chamber & 3.0643 & 10 & & \\ \hline \multirow{6}{*}{\begin{tabular}{l} **Feed Water Supply System** \\ \end{tabular} } & \begin{tabular}{l} Water tubes \\ \end{tabular} & 5.3936 & 3 & & \\ \cline{2-5}  & Supply water & 5.2401 & 4 & & \\ \cline{2-5}  & \begin{tabular}{l} Backflow peveurter \\ valve \\ \end{tabular} & 2.7529 & 12 & & \\ \cline{2-5}  & Temperature regulator & 2.7632 & 11 & & \\ \cline{2-5}  & Feed water pump motor & 6.5052 & 2 & & \\ \cline{2-5}  & Feed water pump & 12.2870 & 1 & 49.953 & 1 \\ \cline{2-5}  & Strainer & 2.7128 & 13 & & \\ \cline{2-5}  & Feed water tank & 4.4311 & 9 & & \\ \cline{2-5}  & Water level controller & 1.0964 & 25 & & \\ \cline{2-5}  & Feed water hose & 2.2889 & 18 & & \\ \cline{2-5}  & Water softner & 2.0131 & 20 & & \\ \cline{2-5}  & Deeraator & 2.4687 & 15 & & \\ \hline \multirow{6}{*}{\begin{tabular}{l} **Bllow-down System** \\ \end{tabular} } & \begin{tabular}{l} Return water \\ temperature sensor \\ \end{tabular} & 5.2306 & 5 & & \\ \cline{2-5}  & \begin{tabular}{l} Drain pump \\ \end{tabular} & 2.5268 & 14 & 9.0564 & 3 \\ \cline{2-5}  & Condensate filter & 1.2990 & 24 & & \\ \hline \multirow{6}{*}{\begin{tabular}{l} **Emission Control System** \\ \end{tabular} } & \begin{tabular}{l} Induced Draft (ID) fan \\ \end{tabular} & 2.3364 & 17 & & \\ \cline{2-5}  & \begin{tabular}{l} Forced Draft (FD) fan \\ \end{tabular} & 4.4738 & 8 & & 8.1287 & 4 \\ \cline{2-5}  & \
\begin{tabular}{l} Mechanical dust \\ collector (MDC) \\ \end{tabular} & 1.3185 & 23 & & & \\ \cline{2-5}  &
\begin{tabular}{l} Burner \\ \end{tabular} & 2.3683 & 16 & & 7.3796 & 5 \\ \cline{2-5}  & Feed motor & 5.0113 & 7 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 12: Criticality Index and their criticality ranks of boiler sub-systems and components. compared in Table 13 and Figure 2. This study shows the impact of the other risk criteria like maintenance time, safety, and operational loss on the components' criticality.