The following diploma thesis is focused on the usage of selected methods and tools to improve quality of the company called Slavia Production Systems. The thesis consists of two main parts – the first one is focused on theoretical background which presents terms such as the definition of quality, quality management, features of quality management system as well as definitions of each tool and a method used in quality improvement within the company. The second part of the thesis is a practical part which follows theoretical background. In this part, there is a description of the company, its structure or production programme; gradually there is a description of quality system used in the company. Then the thesis presents an analysis of controlled findings in 2016 which is related to the next chapter describing application of selected methods and tools used to improve the quality in the company. This chapter presents detailed descriptions of every tool used for quality improvement such as Pareto diagram, diagram of cause and effect, development diagram and tree diagram. The conclusion of the thesis analyses correction potential which the company might use in future quality improvement.