Using simulated annealing for determination of the capacity of yard stations in a railway industry

Due to the complexity of yard operations and management, a rail-yard operations planning and management tool to support yard capacity and improvement studies is needed. A yard capacity study is to assess how many cars, blocks and trains can be handled with the existing infrastructure and resources. We develop an optimization formulation and a solution procedure for the determination of the capacity of rail yard stations with respect to the optimal number of shunting and reclassification operations at the nodes of the rail network. To tackle this problem, a simulated annealing (SA) algorithm is proposed to solve the model which works efficiently on a neighborhood search within solution space, acceptance probability, and inferior solutions to escape from trap. The proposed approach is applied to an example problem and is shown to be successful, ultimately providing a new managerial tool for planning and analyzing yard capacity more effectively.