Review of methods for demonstrating redundancy in dynamic positioning systems for the o ffshore i ndustry

This report reviews the current approach to demonstrating redundancy on offshore vessels with dynamic positioning (DP) systems, in order to establish whether it meets the requirements for suitable and sufficient risk assessment. The review covers the relevant formal requirements and guidelines, recent incident experience, failure modes and effects analyses (FMEAs) and trials reports, consultations with stakeholders in the industry, and a review of approaches used in other industries. It concludes that the current approach is appropriate in principle, although there are several areas of weakness in the way it is applied in practice. In order to make more effective use of FMEAs, the report recommends that management guidance should be developed, to provide an industry standard for how FMEAs of DP systems should be specified, managed, performed, verified and updated. Meanwhile, specific recommendations are made to each stakeholder on some of the key issues that would eventually be covered in the management guidance. This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic, mechanical, photocopying, recording or otherwise) without the prior written permission of the copyright owner. iii ACKNOWLEDGEMENTS As part of this work, the author gathered views from the key stakeholders listed in Table 1. Their contributions are gratefully acknowledged. The summary views expressed in the report are nevertheless the author's own.