In case of a restaurant we reviewed the factors which are related to stocks and to their economic sizes.  Matrices were used to describe data related to material output ratio in case of both elementary and composite components. With the help of these matrices we created the material output ratio matrix. Prices of components that can be bought from suppliers were arranged into matrices based on their size and variety. We also dealt with the effects of preferential options. Furthermore, we pointed out the terms of actual and planned waste. After that we defined cases in which we could calculate the quantity of unused raw materials.  Following these efforts we overviewed those costs that can occur during the order process and stock keeping. we created various formulas to identify costs. As constraint the storage capacities must have been taken into consideration.  During the optimization we searched for the combination of set inventory products which meet the requirements of defined stock levels, the available storage capacity and costs altogether – including purchasing price as well – in order to take the lowest value. Our model is validated with a case study.