The development of functional structures is part of the product design, therefore, science and engineering. There are several methods of developing operational models that follow basically the same principal, start by simplifying the basic operation of the product in individual subfunctions. This diploma study focused on the FAST method whereby compiled a checklist of quality analysis provided by the methodology. Then it was applied to the product and recorded the observations and the conclusions, so at the last step to have a table summarizing the advantages and disadvantages of the method.