Dynamic risk assessment of marine systems

Abstract

Challenges related to risk assessment of dynamic systems have become more numerous in the past decades due to rapid advances in technology. With these advances follows an increased use of automatic control systems which complicates and makes causality in systems less obvious and risk more difficult to assess. An example of a system, in which dynamic behaviour and automatic control complicate the risk assessment, is the dynamic positioning (DP) system. The DP-system enables maritime and offshore vessels to automatically maintain position by using the on-board thrusters. Focusing on maritime DP-systems, the objective of this paper is to demonstrate that risk often depends on time dependent variables and parameters, such as state variables, disturbances, and event timing. The need for new methods for assessing risk, as well as performing online risk control, is illustrated. Key requirements for operational online risk assessment frameworks are proposed.