The combination of the MOORA method and the Copeland Score method as a Group Decision Support System (GDSS) Vendor Selection

The selection of the right vendor is crucial for the success and competitiveness of manufacturing organizations. Vendor selection decision making has a wide scope and a high level of complexity, which is due to the involvement of various decision makers who have their own preferences. The involvement of various decision makers with their respective preferences, also causes differences in priority over the criteria used. In this paper, it is proposed to use the concept of Group Decision Support System (GDSS) to determine the best vendor based on the aggregation of the preferences of each decision maker. The proposed GDSS concept is to combine the Multi-Objective Optimization method on the basis of Ratio Analysis (MOORA) with the Copeland Score method. The MOORA method is used as a ranking method based on the criteria and weight ratio of each decision maker. The results of ranking using the MOORA method each decision maker is then aggregated using the Copeland Score method, to get the final vendor ranking. The results show that Alternative 5 (Yogatama) has the highest score, so it is ranked first and shows as the best alternative. Sensitivity analysis showed that the proposed GDSS concept was solid, with a low percentage of change.