Across the global oil and gas industry, considerable effort has been focused on the prevention of major incidents. Because of very complex operations, heavy tools, high pressures and hazardous substances, drilling operations are creating a high potential for such incidents. The challenge does not only lie in identifying the risks leading to incidents, but in creating a common risk and safety awareness within a company as well as between a company and its contractors. Controlling the level of risk a company is willing to accept on its drilling operations is one of the reasons for implementing management systems. These management systems build the framework for standards, processes and regulations that operations have to follow. To ensure compliance to the management systems across the board, audit initiatives have to be implemented. Since 2008 OMV E&P has been applying a rigorous audit initiative on its contracted drilling and workover rigs. While the audits are focused on safety issues and review the three major aspects, the equipment, the crew competence and the management system, the benefits of the initiative go beyond safety only. Adequate contractors work safely but also and more efficiently, resulting in less non-productive time, lost time incidents and ultimately in less costs. Additionally OMV is also auditing subsidiary offices on their compliance level with E&P standards. Both audit initiatives generate a vast amount of data along the way. The intention of this thesis is to use the available data revealing the influence of the audit initiative on safety and economics. Therefore, the data is analyzed with statistical methods, like trend or correlation analysis, and the results are then combined with some quality background information to reveal deeper insights. In the first part of the thesis the key performance indicators are analyzed for possible cross-correlations, while in the second part the key performance indicators of each subsidiary are analyzed separately.