Porovnání modelů řízení zásob a podnikové praxe maloobchodní společnosti

The aim of this paper is to describe and compare the procedures and results, especially the total costs and order levels, calculated by the economic order quantity (EOQ), the economic order quantity model with compounding (EOQ_C) and spreadsheet inventory simulation and optimization model (Spreadsheet model) with the optimization algorithm in OR Tools. The optimization algorithm is currently being developed by an unnamed company and the comparison is performed because we want to check whether the optimization algorithm is currently the best solution or whether it has any shortcomings that can be eliminated during development. The paper will first describe the principles of inventory and material management from a logistics perspective and the selection of key items according to ABC and XYZ analysis. Then the thesis discusses the EOQ, EOQ_C, Spreadsheet model and the optimization algorithm in OR Tools. Finally, on the test data of the model company, key items are selected by performing analyses. These items are used to calculate the best (optimal) order quantity and associated costs, to compare the results and then to determine the most appropriate calculation method. The results are compared on the basis of both the total cost and the accuracy of the ordered quantity against the expected reality. The reason for comparing these models is that we want to test the quality of the optimization algorithm and possibly find gaps that the algorithm may have and improve it based on that. Furthermore, the paper will describe the reasons why the results of the models differ. The optimization algorithm in Google OR-Tools uses the Python programming interface, so the models are solved using the same software except for the Spreadsheet model, which is solved in MS Excel by the solver add-in.