This diploma thesis deals with the theme simulation models. It is separated to three parts: theoretic, a part describing a simulation program and a practical part. The opening part's role is to introduce to a reader the problem about simulation models, inform him about simulation project building and define some key words. The second part explains a work with simulation program Simprocess. In the third part the reader finds out, how to use theoretic knowledge. It is demonstrated on the simulation of the operations of the company Prádelna Lety. A goal of this part is to make a simulation model, which describes the reality and can solve the main problems identified in the beginning of this part. All of this is the object of the analysis. After that is possible to give some advises about improving the operations.