Two-echelon vehicle routing problem with time windows and simultaneous pickup and delivery

This paper proposes a tabu search algorithm for the two-echelon vehicle routing problem with time windows and simultaneous pickup delivery (2E-VRPTWSPD), which is new variant of problem. 2E-VRPTWSPD involves three stages routing: (1) first-echelon vehicles start from depot to deliver cargoes satellites; (2) second-echelon satellites serve customers within in simultaneously manner finally return their cargoes; (3) collect on satellites. To solve this problem, we formulate it mathematical model. Then, implement variable neighborhood tailored solution representation large-scale instances. Dummy are applied our speed up search. Finally, generate two benchmark instance sets analyze performance algorithm. Computational results show that can obtain optimal 10 out 11 small-scale instances produce promising solutions 200-customer few minutes. Additional experiments indicate usage dummy satellite save 19% computation average.