Solution Strategy for One-to-One Pickup and Delivery Problem Using the Cyclic Transfer Approach

One-to-one Pickup and Delivery Problem (PDP) with loading constraints is studied. Mathematical model is presented using combinatorial configurations approach for pickup and delivery and the phi-function technique for loading constraints. Two-stage solution strategy is used. The first stage has two levels: a) clustering the set of pickup and delivery points regarding to the set of vehicles and b) solving the PDP problem with 3D loading constraints for each vehicle within the appropriate cluster. The second stage improves the solution found at the previous stage and is based on the cyclic transfer approach and cyclic permutations. Computational results are presented to support efficiency of the approach.