Drilling decisions made before a rig reaches location make a significant contribution to an oil company's financial success. Of value to the company is not the ability to drill wells, but the ability to plan with confidence in the knowledge of what is possible. In spite of this, operators have tended to over-work day to day decisions about drilling out of proportion to their significance. Recognition of this fact has resulted in the present wave of contracting initiatives. A major challenge for the industry is to achieve the necessary transfer of responsibility without compromising the operator's licence to operate. These changes will compel the service sector to develop a new culture of technical integrity and continuous improvement. To operate safely, measure performance and manage drilling risk, the transformation will oblige the service sector to adopt many technologies presently owned by oil companies.