Abstract This paper describes the impact on Total Quality Management (TQM) that improved customer/supplier relationships have had for a UK Exploration and Production Operator. The Drilling in the Nineties initiative introduced in early 1990 has been broadened to include well services and equipment supply areas with a resultant name change to Well Engineering in the Nineties (Win 90s). Experience has been gained with the implementation of this programme with two drilling contractors. In E & P companies the focus for TQM improvement is invariably on the supply side, ie the well and production, unlike other industries where the focus is on the customer. Quality in E & P is thus driven, not by the end user; but by upstream (supply) pressure, for reasons of cost, safety and the environment. The implementation of co-operative supplier strategies is increasing the demand for Total Quality Management in both supplier and customer companies. The paper will describe how developing a co-operative relationship has resulted in a joint effort in initiating more continuous improvement activity, reducing waste and adding value. Examples are discussed of appropriate planning and training initiatives and tools used to develop a co-operative relationship. The need for support and intervention from senior management such as modifying existing policies to support the new relationships is reviewed. Win 90's implementation has shown that it is not the introduction of Total Quality Management with the operator or supplier individually but the integration along the supply chain which enables ‘leading edge’ performance.