A combined Mixed Integer Programming model of seaside operations arising in container ports

This paper puts forward an integrated optimisation model that combines three distinct problems, namely the Berth Allocation Problem, the Quay Crane Assignment Problem, and the Quay Crane Scheduling problem, which have to be solved to carry out these seaside operations in container ports. Each one of these problems is complex to solve in its own right. However, solving them individually leads almost surely to sub-optimal solutions. Hence the need to solve them in a combined form. The problem is formulated as a mixed-integer programming model with the objective being to minimise the tardiness of vessels. Experimental results show that relatively small instances of the proposed model can be solved exactly using CPLEX

Study and ranking of factors influencing the optimum operation of container terminals by using Bernardo’s approach

Thousands of containers put into and exit from modern container terminals in seaports everyday. Because of increasing usage of containers in international trade and goods transportation, pioneer ports try to improve their productivity by optimum usage of their tools, capabilities, strengths and opportunities. It is important for ports to satisfy economic, social and political objectives in a profitable way. A wide variety of factors affect optimum container operations in sea ports. The basis of this study was ranking of factors and selection of main factors based on Bernardo's decision making method (group multi-attribute by ranking scale), in Bushehr port. Results of this research showed that factors including machinery, building container terminal in Negin Island, containers area, specialized human resources and law and regulation, have more effect in optimum container operation in Bushehr seaport

An evolutionary approach to a combined mixed integer programming model of seaside operations as arise in container ports

This paper puts forward an integrated optimisation model that combines three distinct problems, namely berth allocation, quay crane assignment, and quay crane scheduling that arise in container ports. Each one of these problems is difficult to solve in its own right. However, solving them individually leads almost surely to sub-optimal solutions. Hence, it is desirable to solve them in a combined form. The model is of the mixed-integer programming type with the objective being to minimize the tardiness of vessels and reduce the cost of berthing. Experimental results show that relatively small instances of the proposed model can be solved exactly using CPLEX. Large scale instances, however, can only be solved in reasonable times using heuristics. Here, an implementation of the genetic algorithm is considered. The effectiveness of this implementation is tested against CPLEX on small to medium size instances of the combined model. Larger size instances were also solved with the genetic algorithm, showing that this approach is capable of finding the optimal or near optimal solutions in realistic times

The cross‐entropy method for combinatorial optimization problems of seaport logistics terminal

Studies on seaport operations emphasize the fact that the numbers of resources utilized at seaport terminals add a multitude of complexities to dynamic optimization problems. In such dynamic environments, there has been a need for solving each complex operational problem to increase service efficiency and to improve seaport competitiveness. This paper states the key problems of seaport logistics and proposes an innovative cross‐entropy (CE) algorithm for solving the complex problems of combinatorial seaport logistics. Computational results exhibit that the CE algorithm is an efficient, convenient and applicable stochastic method for solving the optimization problems of seaport logistics operations. First published online: 10 Feb 201

MODELO MATEMÁTICO PARA PLANEJAMENTO DA ATRACAÇÃO DE NAVIOS DE GRANEL CONSIDERANDO O CÁLCULO DE PRÊMIO E MULTA

"O crescimento da demanda mundial por produtos com custos cada vez menores, está diretamente relacionada à aquisição das matérias primas, independentemente de onde sejam ofertadas, mas que apresentem o menor custo final possível, de modo a viabilizar a competitividade das empresas ao redor do mundo, inclusive no Brasil. Nesse cenário, o comércio mundial utiliza em grande parte o transporte marítimo, e para movimentar essas matérias primas, os portos se tornam cada vez mais exigidos, visto o aumento da representatividade do custo logístico no custo total dos produtos. Os portos dedicados à movimentação de navios graneleiros são influenciados diretamente pelas regras do contrato de locação de navio, conhecido como contrato de Charter Party. Este contrato define as regas e valores para prêmio e multa, utilizados para verificar a aderência na execução das operações portuárias, como mecanismo para gerar maior comprometimento dos portos no atendimento aos navios e na movimentação das cargas. Portanto, no contexto analisado, é importante disponibilizar aos portos uma ferramenta que busque maximizar a relação entre o prêmio recebido e a multa paga. Vale ressaltar que na literatura cientifica pesquisada não foram localizados estudos que solucionem o Problema de Alocação de Berços (PAB) a partir de uma abordagem financeira de prêmio e multa. Esta dissertação tem por objetivo propor um modelo matemático aplicado para o planejamento da atracação de navios em contrato Charter Party, visando o aumento do recebimento de prêmio e redução do pagamento de multa pelo porto, em função do tempo total em que os navios permaneceram à disponibilidade do porto para operação. Instâncias foram desenvolvidas tendo como base as características operacionais do Porto de Tubarão e aplicadas no CPLEX 12.6, cujos resultados mostram a eficiência da aplicabilidade desta ferramenta em portos reais, desde o suporte na programação da sequencia de atracação dos navios à tomada de decisão em projetos de investimento. Palavras-chave: Problema de Alocação de Berço (PAB), Charter Party, Logística Portuária, Portos Graneleiros.

Models and Solutions Algorithms for Improving Operations in Marine Transportation

International seaborne trade rose significantly during the past decades. This created the need to improve efficiency of liner shipping services and marine container terminal operations to meet the growing demand. The objective of this dissertation is to develop simulation and mathematical models that may enhance operations of liner shipping services and marine container terminals, taking into account the main goals of liner shipping companies (e.g., reduce fuel consumption and vessel emissions, ensure on-time arrival to each port of call, provide vessel scheduling strategies that capture sailing time variability, consider variable port handling times, increase profit, etc.) and terminal operators (e.g., decrease turnaround time of vessels, improve terminal productivity without significant capital investments, reduce possible vessel delays and associated penalties, ensure fast recovery in case of natural and man-made disasters, make the terminal competitive, maximize revenues, etc.). This dissertation proposes and models two alternatives for improving operations of marine container terminals: 1) a floaterm concept and 2) a new contractual agreement between terminal operators. The main difference between floaterm and conventional marine container terminals is that in the former case some of import and/or transshipment containers are handled by off-shore quay cranes and placed on container barges, which are further towed by push boats to assigned feeder vessels or floating yard. According to the new collaborative agreement, a dedicated marine container terminal operator can divert some of its vessels for the service at a multi-user terminal during specific time windows. Another part of dissertation focuses on enhancing operations of liner shipping services by introducing the following: 1) a new collaborative agreement between a liner shipping company and terminal operators and 2) a new framework for modeling uncertainty in liner shipping. A new collaborative mechanism assumes that each terminal operator is able to offer a set of handling rates to a liner shipping company, which may result in a substantial total route service cost reduction. The suggested framework for modeling uncertainty is expected to assist liner shipping companies in designing robust vessel schedules

Simulasi Proses Pemuatan Kapal Di Pelabuhan PT. Wina Gresik Dengan Tujuan Mengurangi Demurrage

Kinerja dari pelayanan pelabuhan umumnya dievaluasi dari waktu pelayanan aktivitas bongkar-muat kapal. Pada dermaga bulk cargo PT. WINA, kinerja proses pemuatan dievaluasi dari waktu pemuatan kapal, serta besarnya demurrage. Hal tersebut terjadi dikarenakan adanya antrian kapal yang menyebabkan keterlambatan dalam penyandaran kapal selanjutnya. Permasalahan yang terjadi di pelabuhan PT. WINA Gresik adalah terjadinya peningkatan waktu pemuatan yang melebihi waktu standar, serta peningkatan demurrage yang ditanggung oleh perusahaan. Ada dua alternatif yang diajukan untuk meminimalkan waktu pemuatan dan demurrage, yaitu penambahan jalur pipa yang digunakan untuk pemuatan dan pembangunan tangki shipment dengan jarak yang lebih dekat ke dermaga. Tujuan yang ingin dicapai adalah menentukan skenario alternatif terbaik dalam usaha perbaikan kondisi saat ini. Penentuan alternatif terbaik dilakukan dengan menggunakan metode simulasi diskrit. Langkah-langkah untuk melakukan simulasi adalah sebagai berikut: (1) mengumpulkan data dari proses pemuatan kapal; (2) membuat model konseptual simulasi proses pemuatan pada kondisi eksisting; (3) melakukan proses simulasi pada kondisi eksisting; (4) melakukan uji verifikasi dan uji validasi; (5) mengembangkan model simulasi untuk kedua alternatif serta melakukan simulasi; dan (6) melakukan analisis dari hasil simulasi yang telah dilakukan. Simulasi diselesaikan dengan menggunakan perangkat lunak ARENA 14.0. Hasil simulasi menunjukkan bahwa, alternatif pembangunan tangki shipment dengan jarak lebih dekat ke dermaga adalah alternatif terbaik. Alternatif tersebut menghasilkan pengurangan demurrage sebesar 57% dari kondisi eksisting. Berdasarkan perhitungan return of investment (ROI) didapatkan 139,9% dan payback period untuk alternatif tersebut adalah 0,41 tahun. =============================================================================================== Performance of sea ports usually evaluated based on service time of the loading-unloading activity. Loading process performance at PT. WINA bulk cargo port evaluated based on ship loading time and demurrage cost. Demurrage cost should be paid to the ship owner due to there are waiting lines which cause delay in berthing the ship within given lay time period. Problems in PT. WINA Gresik port are the increasing case of extending loading time beyond standard time limit, and the increasing cost of demurrage as an effect of the ship berthing delay due to port congestion. Specifically there are two alternatives proposed to solve the loading time and demurrage problem, these alternatives are: (1) add new pipeline to the existing shipment line, (2) building new shipment tank which is closer in distance to the jetty. The objective of this thesis is to determine the best alternative scenario to improve existing condition, in order to minimize loading time and demurrage. Discrete simulation method used to analyze the problem, within these chronological steps: (1) collecting data from loading activity process; (2) modeling simulation flow chart of the existing loading activity; (3) running simulation process on the existing condition; (4) verifying and validating simulation model; (5) testing alternative scenarios based on constructed simulation model; and (6) analyzing simulation result. Simulation software used is ARENA 14.0. Best scenario chosen based on performance criteria: shortest loading time, and the lowest demurrage cost. The result of simulation shows that the building of the new shipment tank with shorter distance to jetty is the best alternative. Demurrage cost reduced by 57% compared to existing, and return of investment (ROI) 139.9% while payback period is 0.41 year

Models and new methods for the quayside operations in port container terminals.

Ph.DDOCTOR OF PHILOSOPH