## 4 Case Study
In this study, it was decided to use extended criteria for sustainable supplier selection with technical criteria since equipment and machinery are purchased (Table 3). Only on the basis of a detailed analysis of potential suppliers is it possible to make a decision on which supplier will have a long-term impact on the efficiency of this company's business. These criteria were set up at by considering what MAMEX needed to implement the Agriculture 4.0 system and how to select a supplier for the needs of this system. First, we investigated what each supplier should have, in order to select the best one. However, due to the specificity of this research, it was decided not to go into too much detail, and 10 criteria were selected to evaluate the supplier. Some of these criteria are classic criteria by which suppliers have been evaluated in previous research and some are specific to the Agriculture 4.0 system. After the criteria were selected, an attempt was made to find some of the studies in which they were mentioned and used. With the criteria of innovation, reliability and quality and guarantees, we evaluated whether the selected suppliers have innovative and high-quality equipment that will not break down often and that will meet the set standards of this system. Service support and education and training are focused on the service level that suppliers must provide when selling equipment and machinery for the Agriculture 4.0 system. Suppliers must train company employees so that they can use this equipment and machinery effectively and efficiently. Price and flexibility in payment are related to the financial aspect. Each piece of equipment and machinery must be paid for, so it is very important that the supplier has favorable prices and that it allows payment to be made, for example, in installments or to have agreed credit arrangements as the purchase of this equipment and machinery entails higher financial expenses because it represents an investment. The impact on employment considers the social aspect when selecting suppliers; it is necessary that the implementation of this system contributes to increasing productivity in production, and since MAMAX is partly a processing company, this would further affect the increase in the number of workers and lead to employment. Energy efficiency and sustainability are environmental aspects when selecting suppliers. It is necessary that this equipment and machinery be energy efficient so that there is no increase in costs when using them in practice. In addition, it is necessary to take care of environmental preservation so that future generations can use available resources. When conducting the research, the specific characteristics the supplier should have were determined. First, it was decided that it would be a local supplier that specializes in new approaches in agriculture and that has many years of experience in the procurement and delivery of equipment and machinery. Then, this supplier must also provide service for this equipment and machinery so that certain malfunctions or regular services can be repaired in a timely manner so that time is not wasted. Finally, this supplier must also provide advisory assistance so that MAMEX can use the purchased equipment and machinery efficiently. Based on these criteria, eight suppliers were selected to be considered. These suppliers are marked with the labels SUP1 to SUP8 in order to protect the identity of these suppliers. This is because if a supplier is not selected for MAMEX, it does not mean that another company will not choose that same supplier as its partner. Each company is specific and has its own needs that a certain supplier can meet. The selected potential suppliers are as follows:  
* Supplier 1 (SUP1) sells and services tractors, and offers a wide range of spare parts and attachments
* Supplier 2 (SUP2) specializes in the sale of agricultural machinery, attachments and spare parts, with technical support and consulting to users.