Robust Optimization For Liner Ship Route Schedule Design Considering Port Time Uncertain

In the past few decades,the container liner transportation had been emerged as very attractive technique for the international maritime transportation and played a very important role for the word trade.With the resuscitating process of the international economic,the international container shipping also shown a fast growth.In the current liner transport market,the oversupply of capacity leads to the fierce competition in the liner shipping market,and the punctuality rate directly affects the level of liner service.Although reliable schedules is crucial for liner companies,the current situation of container liner punctuality rate in the market is not optimistic.The 2018 liner punctuality rate has hit a record low.Meanwhile,with the increasing trend of large ships,the capacity allocation of liner companies is also changing,and the adjustment of routes and capacity allocation will also lead to the adjustment of liner schedule.Under such circumstances,liner companies are actively exploring ways to reasonably formulate shipping schedule,so as to control costs and increase benefits.In practical operation,the uncertainty of ship's time in port is the most important factor affecting the liner's punctuality.This paper analyzes the relevant concepts and theoretical basis of the of shipping schedule design,considering the impact of uncertain port time on liner shipping schedule,and carries out the following innovative research:(1)Considering the uncertainty of time in port and port time window constraints,using the uncertainty budget robust optimization method proposed by Bertsimas and Sim in 2004,the robust optimization model was established.The wait time before and after the docking,loading and unloading operation time,enter the port and departure time,the uncertainty of ship handling operation time are considered.(2)A improvement to the use of the robust optimization method was raised,to set the ship in the port of time for a certain interval,using an uncertain budget ? to reflect the uncertainty of the entire voyage,and optimize the schedule under the worst case of liner shipping.Lingo11.0 is used to find programming solution.(3)With the trans Pacific liner route of a liner company as an example,and by using Lingo software to solve the problem,we analysis the influence of budget ?,fuel costs a and port time window on the result of optimization.The results shown that the model optimization results were more reliable than the real plan and the model had good solution robustness and model robustness,which couldn assist liner companies to make decisions in the design of shipping schedule.