This diploma thesis deals with the evaluation of supplier risk for a chosen company Vinařství Soška using the fuzzy logic principles. This company like many others is forced to shift its sales to the Internet environment due to the government restrictions established to reflect the pandemic situation. For a successful Internet business, it is necessary to choose an optimal ecommerce software based on the company requirements. For this purpose, two fuzzy logic models are built in Microsoft Excel and MATLAB software. Their aim is to evaluate the potential risk of all of the suppliers. Based on this evaluation, the results are transformed into specific recommendations on how to choose the optimal solution for the company. The first chapters de...