Optimization Of Tramp Ship Scheduling Considering Berth Free Time

Maritime transport is an important part of promoting international trade and global economic development.The growing population,living standards and industrialization promote the demand for increasing maritime transport capacity and import and export of bulk goods.Irregular transportation is the main way to transport bulk dry and bulk goods.With the improvement of fleet capacity,the rapid growth of international maritime trade is promoted.The effective design and operation of fleet can improve productivity and living standards.Therefore,optimizing ship scheduling is the main factor to improve production efficiency.Under the influence of other factors such as ship capacity,fleet planning,port demand and route arrangement,the problem of ship scheduling,will also be very different.At present,many domestic ship companies still rely on the management experience of the dispatcher to make scheduling plan,which needs to be improved in terms of technology and scientific rationality.Therefore,it is necessary to study the ship scheduling problem.This paper focuses on the irregular ship scheduling problem with multi ships,multi ports and multi cargoes.In order to reduce the operating cost of shipping enterprises that provide irregular cargo services on the regional shipping network,it studies the scheduling optimization of irregular ships.On the premise that the freight demand between different ports in the region is known,the berth time window and the actual situation that each port can be loaded and unloaded are mainly considered,as well as the realistic constraints such as the cargo service time window and the ship capacity of the port,In order to minimize the total operating cost of all ships in the planning period,an integer programming model is constructed,and a genetic algorithm embedded in the tabu search rule is designed to solve the model.The order of all ships' berthing ports and the cargo transported are given.The genetic algorithm in this study adopts the selection,crossover and mutation mechanism of the classical genetic algorithm,sets the penalty function to deal with the relevant constraints,and combines the tabu search algorithm to improve the speed and reliability of the global search.Through numerical experiments,the improved genetic algorithm is compared with CPLEX and traditional genetic algorithm to verify the effectiveness of the model and algorithm.The results show that considering the berth time window and the port can be loaded and unloaded can effectively reduce the operating cost.