This paper will explain the concept of quality, importance and basic theories of quality management. Important ISO norms and standards will be listed, as well as the benefits of their implementation, the impact of quality on competitiveness and important strategies for achieving competitiveness in the market. The importance and development of quality management in the IT (information technology) industry with an emphasis on software as a service and its impact on achieving a competitive advantage on the example of comparing application service providers and software as a service will be covered. On the example of the IT company Mediatoolkit d.o.o. the process of introducing quality management in the software industry as a service in the Republic of Croatia and the importance, sustainability and continuous improvement of this system will be presented. The concluding part will emphasize the importance of quality management in the company's business and the need to establish and apply ISO standards in the software industry as a service to ensure the company's competitiveness in the market and continuous improvement of services.