Case Studies

In this chapter, the online risk levelRisk level of different dynamic positioningDynamic positioning (DP) systems is assessed based on the methods presented in Chap. 2 . The proposed methods are able to provide an online risk levelRisk level of the system in different operating and environmental conditionsEnvironmental conditions that could assist decision makers to make better (safer) decisions. In the first example, (All proprietary, identification, sensitive, and confidential information are removed.) Subsect. 7.1, a DP drilling unitDrilling unit incidentIncidents is simulated. In this incidentIncidents, the operator has two choices of manual or automaticAutomatic disconnectionDisconnection. A risk modelRisk model is utilized to estimate the risk levelRisk level of these two scenarios and provide useful information to the operator to select the safer option. In this example, two operators with different behaviors are compared, and the effect of human performance on the system risk levelRisk level and scenario selection is discussed. In the second, third and fourth examples (AutomaticAutomatic mode: the DP system automatically maintains the vessel position using the control system and related actuators.) (Subsect. 7.2, 7.3, and 7.4, respectively), supervised failure scenario generationSupervised failure scenario generation is presented. In these examples, different DP incidentsIncidents are investigated, initial eventsInitial event, operating and environmental conditionsEnvironmental conditions are used as risk modelRisk model inputs, and the modelModel predicts the most probable failureFailure scenarios. In each example, the most probable failureFailure scenarios are compared with real incidentsIncidents. The generated scenarios could help operators to make better decisions to avoid most probable failureFailure scenarios.