Solving the multi-compartment capacitated location routing problem with pickup–delivery routes and stochastic demands

• LRP with pickup and delivery routes considering multi-item and stochastic demands.
• A new solving process with three stages is proposed.
• Design the “seed” concept to help on selecting the open depots.
• Group customers into assignment-determined and assignment-undetermined sets.
• Most of the best solutions are occurred on bandwidth rate λ = 0.6–0.9.

This paper considers an advanced capacitated location routing problem in a distribution network with multiple pickup and delivery routes, and each customer placing random multi-item demands on it. The pickup and delivery services need two fleets of vehicles and will form two different sets of routes. However, the unpredictability of variation in the multi-item demands makes the routing of multi-compartment vehicles to accommodate such demands complex. To solve this multifaceted problem, a new process employing the TABU search is proposed in this research study. This proposed approach includes three stages: location selection, customer assignment, and vehicle routing. The innovative concept is to divide all customers into assignment-determined and assignment-undetermined groups in order to narrow down the search area of a solution domain so the TABU search can be more efficient and effective. Two sets of benchmarks are then generated to verify the quality of the proposed method. According to the experiment results, the proposed solution process can both resolve the problems and yield good results in a reasonable amount of computing time. The analysis of the solution process parameters is also provided. In addition, the comparisons between stochastic demand and deterministic demand cases are calculated and discussed as well.