Research On Multi-Ship Scheduling Of Liners Considering Tidal Effects

The liner shipping company's container shipping is a multi-billion dollar industry that is responsible for the major part of world trade between suppliers and customers.With the development of the shipping industry,the competition of different liner companies has become increasingly fierce.The liner company generally announces the schedule of the vessel half a month in advance for the vessel could load and unload the cargo with the scheduled time and customers could reserve the cabin according to the delivery time of this form.Affected by uncertainties such as weather and speed,liner shipping business may cause delays,which will have a huge impact on the company itself and its customers.In order to better meet the needs of customers and provide better service,liner companies will arrange goods according to the time of the schedule as soon as possible.How to effectively improve ship transportation scheduling is of great practical significance for rational planning of ship capacity,reducing the operating cost of liner companies and improving customer service level It is the focus of research of all parties concerned today.The Multi-ship scheduling problem caused by the fluctuation of cargo demand and tide was studied for liner enterprises when the schedule is announced in advance.Firstly,the structure of offshore shipping routes of a liner enterprise was systematically analyzed.Then,with the consideration of the real situation of large ships need to tide in and out of ports,rent ships was permitted under appropriate conditions,and the limitation of the liner schedule,a nonlinear programming model of liner multi-ship type scheduling was built with the objective of minimizing the total transportation cost.Finally,in view of the characteristics of the model,an improved genetic algorithm(IGA)embedded with gene modification was designed to solve the problem.Experimental results show that the ship scheduling scheme can improve the ship utilization ratio by 25%-35%compared with the traditional experiential ship scheduling scheme,the CPU processing time of IGA algorithm is reduced by 32%on average compared with CPLEX in medium scale,and the transportation cost of IGA algorithm can be reduced by 12%compared with ant colony algorithm in medium and large scale.All these demonstrate the validity of the proposed model and algorithm which can provide a reference for liner enterprises in ship scheduling.