Practical challenges in determining periodic maintenance intervals on the Norwegian Continental Shelf (NCS): Some expert views and opinions

Abstract

Maintenance is one of the key success factors for ensuring safe and reliable operations on the Norwegian continental shelf (NCS). Periodic maintenance is still a large part of the maintenance portfolio even if the ambition is to shift towards dynamic strategies. Therefore, one can conclude that, currently, the availability of offshore production facilities on the NCS is significantly influenced by maintenance programs that are based on predetermined periodic maintenance tasks. This paper reviews current practices and experiences for determining intervals for performing maintenance tasks. The mapping is performed by comparing theoretical and practical industrial approaches to determine the preventive maintenance task intervals. The paper highlights some practical issues and challenges that maintenance engineers face in the determination of task frequencies/intervals on the NCS. The study shows that the biggest challenge for the maintenance engineers is to determine the “optimal interval” for the maintenance tasks. A frequent task will increase the maintenance costs, whilst an extended interval could increase the risks related to unexpected failures. The maintenance engineers use their engineering judgment by combining manufacturer recommendations, regulatory requirements and operational needs to determine optimal intervals. The NCS, however, needs more dynamic maintenance strategies that are data driven but without the inhibiting computational and practical issue