# Remanufacturing Shoemaking Machine: Feasibility Study Using AHP and DEMATEL Approach
## 3 Methodology
### Analytic Hierarchy Process (AHP)  
This study explores the feasibility of remanufacturing shoemaking machines within a closed-loop supply chain under the growing pressure towards net-zero carbon emissions. Remanufacturing offers a sustainable alternative to traditional end-of-life (EOL) practices like recycling or reuse by rebuilding products to original specifications through a combination of reused, repaired, and new parts. This approach reduces waste generation and embodied energy compared to new machine production. AHP serves as a valuable tool for evaluating the feasibility of remanufacturing shoemaking machines in this context. AHP incorporates expert judgment and data to rank options and predict outcomes, aiding decision-makers in selecting the most suitable approach based on their specific goals and challenges. The AHP, developed by [PERSON], is a widely used method for tackling complex decision-making problems with multiple criteria. It helps rank and select the best option when faced with competing objectives [54]. Using AHP, the model prioritizes the criteria, enabling alternatives selection and potentially enhancing a company's commercial operations [55]. Two key features distinguish AHP from other decision-making techniques:  
1. Structured integration of rational and subjective judgment: AHP provides a framework for incorporating both logical and subjective factors into the decision-making process. 2. Consistency evaluation: AHP allows the decision-maker to assess the consistency of their judgments throughout the process. The AHP method involves the following steps [56]. 3. Problem definition: Clearly identify the decision problem. 4. Objective expansion: Consider all stakeholders, objectives, and potential outcomes. 5. Criteria identification: Define the relevant criteria for evaluating options. 6. Hierarchical structuring: Organize the problem into a hierarchy, including the overall goal, criteria, sub-criteria, and alternative options. 7. Pairwise comparison matrices: Create comparison matrices to assess the relative importance of criteria and alternatives. 8. Calculations: Compute the maximum eigenvalue, consistency index, consistency ratio (CR), and normalized weights for criteria and alternatives. 9. Decision-making: If the CR is less than 0.1, indicating acceptable consistency, use the normalized weights to make a final decision. In group decision-making scenarios, AHP employs two primary approaches: aggregating individual judgments and aggregating individual priorities [57]. By using the row geometric mean method (RGMM) prioritization procedure, the group priorities obtained through the aggregation of the individual priorities verify the requirement of consistency proposed in AHP methodology if the individual priorities also verify this requirement [58]. The AHP addresses the challenge of incorporating subjective factors into decision-making. It utilizes expert judgment to establish priority scales for both tangible and intangible criteria through pairwise comparisons. AHP assesses the consistency of these judgments and refines them when necessary. The derived priority scales are then synthesized to arrive at an overall decision that reflects both quantitative and qualitative factors [59]. This study specifically utilizes the weighted geometric mean method to aggregate individual judgments. Step 1: A hierarchical framework for identifying critical factors and sub-factors is proposed to support the development of supply chains. Step 2: A pairwise comparison of the identified factors is conducted using a nine-point scale, resulting in a comparison matrix [60]. Table 3 shows the scales in pairwise comparisons. Step 3: The normalized weights for the identified factors are calculated to form a weight vector. This vector is then used to rank the factors based on their relative importance. Step 4: To ensure the reliability of the judgments, the consistency of the pairwise comparisons is evaluated.