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Authors
Advisor(s)
Abstract(s)
A alocação de navios nas secções de um porto é um problema muito importante na gestão
portuária, uma vez que impacta diretamente todas as outras atividades. Este problema é
denominado Berth Allocation Problem e é habitualmente estudado sem que seja considerada a
possibilidade de alterar a posição dos navios durante o tempo em que se encontram no cais. O
foco deste Trabalho Final de Mestrado é a aplicação da possibilidade de deslocação de navios
entre secções, durante a sua carga ou descarga, de modo a criar espaço para o atraque de outros
navios que estejam à espera para atracar.
Inicialmente são apresentadas três formulações em programação linear inteira mista: uma
sem a possibilidade de deslocação e duas com essa possibilidade. Como o problema em questão
não pode ser resolvido em tempo útil através de métodos exatos devido à sua complexidade, foram
desenvolvidas heurísticas baseadas na heurística Bottom-Left. São apresentadas três heurísticas,
uma das quais sem possibilidade de deslocação, mas que serve como base para a criação das
restantes.
De modo a retirar conclusões relativamente à utilização da deslocação no problema em
questão, foram utilizados três conjuntos de instâncias, variando na taxa de chegada dos navios e
na dimensão. As formulações desenvolvidas apenas foram aplicadas a instâncias de menor
dimensão e as formulações com deslocação apresentaram melhores resultados quando foram
considerados navios já atracados. As heurísticas foram aplicadas aos três conjuntos de instâncias
e obtiveram melhores resultados do que a formulação sem deslocação nas instâncias de maior
dimensão.
The allocation of ships in the berthing sections of a dock is a very important problem in port management, because it directly impacts all other activities. This problem is known as the Berth Allocation Problem and is usually studied without considering the possibility of shifting the position of docked ships. The focus of this work is to apply the possibility of shifting the berthing sections of ships, during their loading and unloading operations, to create space for other ships awaiting to dock. Initially, three formulations in mixed integer linear programming are presented: one without the possibility of shifting ships and two with that possibility. As the problem cannot be solved in reasonable time using exact methods, heuristics based on the heuristic Bottom-Left were developed. Three heuristics are introduced, the first one does not consider the possibility of shifting ships, but it serves as a basis for the remaining ones. To draw conclusions regarding the possibility of shifting ships in this problem, three sets of instances were used, varying in arrival rate of ships and dimension. The formulations were only applied to the instances with smaller dimensions and the formulations with shifting were able to achieve better results when considering already docked ships. The heuristics were applied to the three sets of instances and were able to achieve better results than the formulation without shifting in the instances with larger dimensions.
The allocation of ships in the berthing sections of a dock is a very important problem in port management, because it directly impacts all other activities. This problem is known as the Berth Allocation Problem and is usually studied without considering the possibility of shifting the position of docked ships. The focus of this work is to apply the possibility of shifting the berthing sections of ships, during their loading and unloading operations, to create space for other ships awaiting to dock. Initially, three formulations in mixed integer linear programming are presented: one without the possibility of shifting ships and two with that possibility. As the problem cannot be solved in reasonable time using exact methods, heuristics based on the heuristic Bottom-Left were developed. Three heuristics are introduced, the first one does not consider the possibility of shifting ships, but it serves as a basis for the remaining ones. To draw conclusions regarding the possibility of shifting ships in this problem, three sets of instances were used, varying in arrival rate of ships and dimension. The formulations were only applied to the instances with smaller dimensions and the formulations with shifting were able to achieve better results when considering already docked ships. The heuristics were applied to the three sets of instances and were able to achieve better results than the formulation without shifting in the instances with larger dimensions.
Description
Mestrado Bolonha em Métodos Quantitativos para a Decisão Económica e Empresarial
Keywords
Berth Allocation Problem Deslocação Heurística Bottom Left Berth Allocation Problem Shifting Bottom-Left Heuristics
Pedagogical Context
Citation
Madeira, Alessia Lopes (2024). “Um problema de alocação de navios num porto admitindo a sua deslocação”. Dissertação de Mestrado. Universidade de Lisboa. Instituto Superior de Economia e Gestão
Publisher
Instituto Superior de Economia e Gestão