13 research outputs found
Effective algorithms for integrated scheduling of handling equipment at automated container terminals
In this paper we consider the problem of integrated scheduling of various types of handling equipment at an automated container terminal, where the objective is to minimize the makespan of the schedule. We present a Branch & Bound algorithm that uses various combinatorial lower bounds. Computational experiments show that this algorithm is able to produce optimal or near optimal schedules for instances of practical size in a reasonable time. We also develop a Beam Search heuristic that can be used to tackle very large problem instances. Our experiments show that for such instances the heuristic obtains close to optimal solutions in a reasonable time.AGV's;Container terminal;beam search;branch & bound;scheduling
Dynamic Scheduling of Handling Equipment at Automated Container Terminals
In this paper we consider the problem of integrated scheduling of various types of handling equipment at an automated container terminal in a dynamic environment. This means that the handling times are not known exactly beforehand and that the order in which the different pieces of equipment handle the containers need not be specified completely in advance. Instead, (partial) schedules may be updated when new information on realizations of handling times becomes available. We present an optimization based Beam Search heuristic and several dispatching rules. An extensive computational study is carried out to investigate the performance of these solution methods under different scenarios. The main conclusion is that, in our tests, the Beam Search heuristic performs best on average, but that some of the relatively simple dispatching rules perform almost as good. Furthermore, our study indicates that it is effective important to base a planning on a long horizon with inaccurate data, than to update the planning often in order to take newly available information into account.beam search;dynamic scheduling;container terminal;dispatching rules
Famas-NewCon: A generator program for stacking in the reference case
The FAMAS-Newcon project aims at developing new logistic control structures for a containerterminal capable of handling jumbo container ships within 24 hours. In one of the subprojectsstacking aspects is studied. This report describes a generator model in which on the basis of a global description arrival and departure moments of individual containers are generated for a medium term (15 weeks). The global description consists of a specification of the modal split in terms of containers handled by jumbo's, deepsea, shortsea, rail, barge and trucks, next a specification of the number and type of containers transported by an individual jumbo and deepsea and finally a specification of the dwell time. The output of the generator program is a file with the following container information: arrival and departure times,import/export modality and the import/export ship in case that is a deepsea or jumbo. This file serves as the input of a stacking program which is described in a sequel report. The advantage of this construction is that several stacking strategies can be compared with the same arrival and departures of containers.generator program;stacking;logistic control structures
Effective algorithms for integrated scheduling of handling equipment at automated container terminals
In this paper we consider the problem of integrated scheduling of various types of handling equipment at an automated container terminal, where the objective is to minimize the makespan of the schedule. We present a Branch & Bound algorithm that uses various combinatorial lower bounds. Computational experiments show that this algorithm is able to produce optimal or near optimal schedules for instances of practical size in a reasonable time. We also develop a Beam Search heuristic that can be used to tackle very large problem instances. Our experiments show that for such instances the heuristic obtains close to optimal solutions in a reasonable time
Effective algorithms for integrated scheduling of handling equipment at automated container terminals
In this paper we consider the problem of integrated scheduling of various types of handling equipment at an automated container terminal, where the objective is to minimize the makespan of the schedule. We present a Branch & Bound algorithm that uses various combinatorial lower bounds. Computational experiments show that this algorithm is able to produce optimal or near optimal schedules for instances of practical size in a reasonable time. We also develop a Beam Search heuristic that can be used to tackle very large problem instances. Our experiments show that for such instances the heuristic obtains close to optimal solutions in a reasonable time
Famas-NewCon: A generator program for stacking in the reference case
The FAMAS-Newcon project aims at developing new logistic control structures for a container
terminal capable of handling jumbo container ships within 24 hours. In one of the subprojects
stacking aspects is studied. This report describes a generator model in which on the basis of a global description arrival and departure moments of individual containers are generated for a medium term (15 weeks). The global description consists of a specification of the modal split in terms of containers handled by jumbo's, deepsea, shortsea, rail, barge and trucks, next a specification of the number and type of containers transported by an individual jumbo and deepsea and finally a specification of the dwell time. The output of the generator
program is a file with the following container information: arrival and departure times,
import/export modality and the import/export ship in case that is a deepsea or jumbo. This file serves as the input of a stacking program which is described in a sequel report. The advantage of this construction is that several stacking strategies can be compared with the same arrival and departures of containers
Operations research supports container handling
In this paper we will give an overview of the use of operations research models and methods in the design and operation of container terminals. We will describe the activities that take place at a container terminal and give an overview of the relevant decision problems, both at astrategic, tactical and operational level. For each of these problems the appropriate operations research contributions are discussed.operations research;ports;container logistics
Dynamic Scheduling of Handling Equipment at Automated Container Terminals
In this paper we consider the problem of integrated scheduling of various types of handling equipment at an automated container terminal in a dynamic environment. This means that the handling times are not known exactly beforehand and that the order in which the different pieces of equipment handle the containers need not be specified completely in advance. Instead, (partial) schedules may be updated when new information on realizations of handling times becomes available. We present an optimization based Beam Search heuristic and several dispatching rules. An extensive computational study is carried out to investigate the performance of these solution methods under different scenarios. The main conclusion is that, in our tests, the Beam Search heuristic performs best on average, but that some of the relatively simple dispatching rules perform almost as good. Furthermore, our study indicates that it is effective important to base a planning on a long horizon with inaccurate data, than to update the planning often in order to take newly available information into account