Dynamic risk analysis for operational decision support

Quantitative risk assessments for offshore oil and gas installations have been developed and used to support decision making about major hazards risk for more than 30 years. Initially, these studies were used to support the design process, aiming to develop installations that could be operated safely throughout their lifetime. As installations were put into operation, the studies were updated with as-built and operational information to provide a basis for making decisions also in the operational phase. This was however only partially successful, and the general impression has been that the studies have not been very actively used in operations. Many explanations have been given, the most common being that the reports were too complicated and written for risk analysis experts, not operations personnel on offshore installations and that the results could not be updated sufficiently often to reflect changes in risk on a day-by-day basis. This may be a part of the explanation, but in this paper, we have looked into the decision context and the types of decisions made in operation, compared to those in the design phase. Based on this, it is concluded that the focus of existing models need to be extended to cover activity risk in a more detailed way, as well as the risk associated with the technical systems. Instead, a revised methodology for developing quantitative risk assessments is proposed, focusing on the parameters and activities that change during operation. The methodology has also been tested on an offshore installation, to investigate the feasibility in practice.