Supplier selection with AHP-TOPSIS methods: An application in natural gas sector

The enterprise is a place that is combining a commodity or service, production factors in a planned and systematic way. The company has three main objectives. These are profit, service to the community and continuity of enterprise. In order to achieve these goals, it should be able to proceed with short and long term goals. The choice of supplier is very important in achieving the short and long term goals of the enterprise and increasing its performance. The choice of supplier is that the business chooses the best supplier among its alternatives, which it explores within the framework of the current workflow. These benefits can be explained as the desired product at the lowest cost, in the fastest time, with the easiest payment options. Choosing the right suppliers will reduce the company's purchasing costs, increase customer satisfaction and increase its competitive performance against its competitors in the market. In this study, the problem of supplier selection for an enterprise active in the natural gas sector is discussed. AHP and TOPSIS methods, which are multi-criteria decision-making methods, are used together to select the most suitable and most efficient supplier. In the study, literature, cost, quality, marketing, logistics and technical criteria, which were determined to be widely used as a result of interviews with experts, were determined as the main criteria and their sub-criteria were defined. The AHP method was used to determine the severity of the main criteria and sub-criteria, while the TOPSIS method was used to rank the suppliers. The benchmark weights of the AHP method and the steps of the TOPSIS method. Calculations were made with MSExcel. As a result, the alternative supplier which is the most suitable for the company has been selected in the problem solved by combining both methods.