Designing a Flexible Catering System for High-Speed Railway Considering Departure Time Selection and Time Deadline Constraints

A new catering mode is introduced into an existing catering service system for high-speed railways. This flexible catering system for high-speed railways aims to make order allocation decisions and service sequencing decisions under tight time constraints. A departure time and route selection model is established to coordinate the delivery times of the orders with the departure times of the trains to mitigate conflicts between the delivery cost and service level. Sequential constraints are reformulated as soft constraints, and an analytical algorithm is designed to solve for the optimal catering vehicle departure time for a given path. The problem is already complex due to its similarity to the vehicle routing problem with time windows (VRPTW). In particular, the route-dependent lead time and constraint-dependent departure time selection make the problem more complex. Therefore, a simulated annealing algorithm based on a variable neighborhood search (VNS-SA) is employed to solve the model. Finally, a random road network experiment is performed to verify the model and algorithm, and the algorithm's performance and computational efficiency with different combinations of subalgorithms are compared and analyzed.