Sequential recovery of disrupted facilities

For a bipartite graph with disrupted facilities, we confront the key concern that disrupted facilities can only be recovered one after one due to resource shortage. The objective of this paper is to design a sequential recovery schedule such that the summation of waiting time and transportation cost of all customers to regain service is minimized. For such a sequential disruption recovery problem, we consider two situations: sequential disruption recovery for uncapacitated facilities (SDRUF) and sequential disruption recovery for capacitated facilities (SDRCF). We model the corresponding optimization problems as integer linear programs, and propose two heuristic algorithms for each situation, based on both Lagrangian relaxation and greedy method, to generate feasible solutions. In the end, computational experiments are carried out to implement the proposed heuristic algorithms. The computational results show that the two heuristic algorithms are efficient and effective for solving the SDRUF and the SDRCF problems, and act as good alternatives for each other based on problem size.