In today's highly competitive economic environment, companies need to ensure the quality of their products if they are to remain on the market. Therefore, they use a number of tools and methods to control and improve their manufacturing processes. In this thesis, we present the seven basic tools of quality (7QC). These form the basis for a number of regularly used quality control methods. In addition to the 7QC tools, we describe SPC, A3 and 5 Why, while demonstrating their use in practice.