An optimization method for resilience enhancement strategies of LNG terminal system considering resilience enhancement rate and cost

Abstract

In the post-disruption phase, the resilience of LNG terminal system largely depends on maintenance resources—the more maintenance resources there are, the stronger the system's restoration capability and resilience. However, as maintenance resources increase, so do the associated maintenance costs. To enhance system resilience while controlling costs, a well-formulated optimization methodology is crucial. A process parameter-driven resilience optimization method for LNG terminal system considering the resilience enhancement rate (RER), cost and the maximum acceptable restoration time (MART) is proposed. The system resilience and RER are assessed by system performance curve, which is determined by time-dependent process parameters obtained from process simulations. The maintenance resources are represented by the number of maintenance team, including human resources, necessary equipment and materials, etc. A cost function model considering inherent cost, the cost of maintenance resources secondment and operating costs is established to represent the cost factors involved in the entire maintenance activity. According to derived results of the resilience assessment and cost analysis, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is employed to solve the multi-objective optimization model developed in this study. The resilience enhancement optimization for the LNG terminal system is utilized to demonstrate the proposed methodology.