The thesis presents a research in the Public Power Corporation S.A. – PPC in Athens, Greece. The main purpose of this study is to examine the employees of PPC use of the IT (Information Technology) system and whether the system supports, helps and facilitates their work or generate problems to them in their daily work. The IT system that is being used in the PPC is SAP (Systems, Applications and Products) and was implemented about two years ago, in 2015. Therefore, my intention is to explore and analyze the usefulness and efficiency of SAP and detect the advantages as well as the problems of this IS which have impact on the quality of the customer services. Furthermore, the latest years that the financial crisis occurs in Greece the common interest for public firm’s development, became a motive for me to propose and undertake this research due to the fact that these kinds of public companies can contribute to the economy of Greece. For the research, I used the interpretive paradigm. The methodology used is ethnography and the two methods are the interviews and the observation. The research was conducted in different departments of PPC. The participants are the employees, the managers and one Director of PPC. The data collected from the two methods are analyzed by using the Lichtman’s six step of analysis. After the data analysis, the results indicate that there are vital problems in the PPC in relation to the use of the IT system which in some cases are more than the advantages. The users of SAP have expressed their experience in relation to the implementation of the new IT system. They recognize the importance on using such an advanced IT system but on the other hand, they express the limitations and the problems because of the vital problems on PPC.