Effect analysis of Reliability, Availability, Maintainability and Safety (RAMS ) Parameters in design and operation of Dynamic Positioning (DP) systems in floating offshore structures

Abstract: The objective of this thesis is to identify, which hazards and failures in operation process will affect Reliability, Availability, Maintainability and Safety of floating offshore structures. The focus is on Dynamic Positioning (DP) system that has the responsibility of keeping the offshore structure in the upright position operation. DP system is one of the most critical subsystems on these types of structures in terms of safety of operation and failure risk costs. Reliability of the system in this thesis has been analyzed in qualitative and quantitative methods. In qualitative method to find the effective parameters on the reliability of the DP system, Reliability Centered Maintenance (RCM ) and its application as a main tool have been used. To achieve the aim it has been tried to define the events and accidents which could be generated by the identified hazards then tried to determine the consequences of the realized accidents. In this step three categories are taken in to account including, safety, operation, and equipment. Next phase should be concentrated on considering and analyzing the relevant processes and the root causes which result in the identified hazard. After clarifying all probable root causes it has been tried to prioritize the root causes and specifying the necessary preventive actions. The aim of this step is either decreasing the occurrence of root causes or increasing the detectability of hazards. In the last part quantitative method has been used to measure the amounts of Reliability, Availability and Maintainability of the system, based on MTBF and MTTR of different components of the system and it has been tried to present the solutions to improve system reliability based on components RCM tables. Further, assuming DP system as human- machine system safety assessment has been included to indicate human factors in the reliability of the system beside probable failure of the components of the system. Keywords:, Dynamic Positioning system (DP ), Maintenance, Condition based Monitoring (CBM), Reliability-Centered Maintenance (RCM), Failure Mode and Effect Analysis FMEA