# Enhancing Efficiency and Cost-Effectiveness: A Groundbreaking Bi-Algorithm MCDM Approach +
## 3 Results and Discussion  
The first result of the DEX method presents its outcomes through graphs. We appreciate the input from experts in assessing the suggested decision methodology, which led to a plan for prioritizing the design choices: WM 4, WM 2, WM 1, WM 3 and WM 5 (or the ranking presented as following WM 4 \(>\) WM 2 \(>\) WM 1 \(>\) WM 3 \(>\) WM 5). This result shows that the WM 4 machine plan is the best alternative. Figures 5-7 present the results of evaluations for the proposed alternatives in different charts and tables in detail. Figure 8 illustrates the initial parameters used to evaluate all proposed alternatives in this study. The cost of purchasing welding and maintenance machines is presented relative to the average value of comparable features. Specifically, WM 1 represents a compact welding machine utilizing MIG welding technology, offering diverse capabilities. On the other hand, WM 2 showcases a medium-sized welding machine using Flux-Cored Arc Welding (FCAW). WM 3 denotes a welding machine that can be easily transformed into an arc welding machine. Additionally, WM 4 and WM 5 correspond to the TIG and laser welding machines, respectively. As depicted in Figure 8, the laser machine is the most expensive option, while the costs of WM 1 and WM 2 are the most economical. Figure 5: Results of the evaluations for all alternatives. Concerning the operating skills required for welding, each type of welding machine demands a distinct set of skills. This study introduces a classification of five skill levels ranging from 1 (highest) to 5 (lowest). Workers encounter significant challenges when operating welding machines assigned to skill level 1, making it a highly demanding task. The machining workpiece thicknesses for the respective welding machines, namely MW 1, MW 2, MW 3, MW 4 and MW 5, are represented by the values of 0.6, 3.2, 3.2, 0.25 and 0.5 mm, respectively. Furthermore, the welding speed is addressed in this section, and different speed levels are proposed for the five welding machines: machines 1 to 5 have corresponding recommended speeds of 300, 400, 200, 250 and 750 mm.min\({}^{-1}\), respectively. It is recommended to select the average parameters for typical machines. Tables 3 and 4 present the calculated results of the weighted sum of PAD standing by \(SP_{i}\) and the weighted sum of NDA, known as \(SN_{i}\). These parameters are calculated based on the Equations (7) and (8). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Alternatives/** & \begin{tabular}{c} **Buying and** \\ **Maintaining** \\ **Price/Cost** \\ **(US Dollars)** \\ \end{tabular} & \begin{tabular}{c} **Operation** \\ **Skill Level** \\ \end{tabular} & \begin{tabular}{c} **The Thickness of** \\ **the Metal Plate** \\ **(mm\({}^{-1}\))** \\ \end{tabular} & \
\begin{tabular}{c} **Welding** \\ **Speed** \\ **(mm.min\({}^{-1}\))** \\ \end{tabular} &
\begin{tabular}{c} **SPi** \\ **(mm.min\({}^{-1}\))** \\ \end{tabular} \\ \hline WM 1 & 0.20353822 & 0.140625 & 0.001256 & 0 & 0.34542 \\ WM 2 & 0.26664777 & 0.140625 & 0 & 0.007895 & 0.41517 \\ WM 3 & 0.18329553 & 0 & 0 & 0 & 0.1833 \\ WM 4 & 0.18726469 & 0 & 0.353015 & 0 & 0.54028 \\ WM 5 & 0 & 0 & 0.051508 & 0.146053 & 0.19756 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The weighted sum of PDA. Figure 6: Results of the evaluations for alternatives in the radar grid. Figure 7: Results of the evaluations for welder options by employing the DEX method. The weights that affect the factors that influence the selected welding machine options are as follows:  
* Price/costs of buying and maintenance: 0.35;
* Skills required for operation: 0.25;
* The thickness of the metal plate (workpieces): 0.25;
* Welding speed: 0.15. Table 5 provides the computed parameters, including \(NSP_{i}\), \(NSN_{i}\) and \(AS_{i}\), which are crucial for the synthesis and ranking of the alternatives. Additionally, Table 6 presents the ranking outcomes for the remaining options.