Catastrophic events such as hurricanes, earthquakes or floods require emergency responders to rapidly distribute emergency relief supplies to protect the health and lives of victims. In this paper we develop a simulation and optimization framework for managing the logistics of distributing relief supplies in a multi-tier supply network. The simulation model captures optimized stocking of relief supplies, distribution operations at federal or state-operated staging facilities, demand uncertainty, and the dynamic progression of disaster response operations. We apply robust optimization techniques to develop optimized stocking policies and dispatch of relief supplies between staging facilities and points of distribution. The simulation framework accommodates a wide range of disaster scenarios and stressors, and helps assess the efficacy of response plans and policies for better disaster response.
Disaster response supply chain management simulation modeling and optimization
Disaster response requires that emergency supplies are distributed rapidly and widely across the affected area. Many national and regional agencies operate supply chains designed to respond to a large variety of disasters. These supply chains differ significantly from commercial supply chains. First, the delivery of goods is not driven by optimizing profits but instead by fulfilling humanitarian needs. Second, while commercial supply chains can be designed and refined to slowly changing customer demand, the supply chains in disaster response must be set up rapidly with little advance warning and often with little precise information. Because disasters usually result in improvements in infrastructure and response plans, the next disaster typically differs significantly from historical patterns. As a result, there is generally insufficient historical data to construct faithful models of damage and the demand for emergency supplies.
In this paper, we consider the problem of inventory level and delivery optimization and simulationg in a supply chain during a disaster response. These are typical logistical challenges faced by government emergency management agencies. Emergency response agencies often rely on supplies that are stored long-term in a small number of large warehouses; we refer to them as Distribution Centers (DC). During a response, the response agencies must transport numerous emergency supplies through a number of intermediate processing points to Points of Distribution (PODs) where they are distributed to the affected population. We refer to the intermediate processing nodes as Staging Areas (SAs). Once established during the disaster response, both PODs and SAs can hold inventories to respond to shifting demand needs. Figure 1 shows an example of a supply chain structure.