There is an increased use of production assurance programmes in Oil and Gas industries. The programme describes the production assurance activities necessary to fulfill the objectives, how they will be carried out, by whom and when. The activities provide input to decisions regarding concept, design, manufacturing, construction, installation, operation and maintenance. It is a challenge to manage and improve production assurance. The aim of this paper is to present and discuss a methodology for improvement of production assurance performance. The proposed methodology consists of four steps. These steps are i) data collection and information management; ii) modeling and data analysis; and iii) generate improvement alternatives; and iv) evaluation alternatives and decision making.