Cookies Policy
The website need some cookies and similar means to function. If you permit us, we will use those means to collect data on your visits for aggregated statistics to improve our service. Find out More
Accept Reject
  • Menu
Publications

Publications by SYSTEM

2022

Energy-Efficient Scheduling of Intraterminal Container Transport

Authors
Homayouni, SM; Fontes, DBMM;

Publication
Springer Optimization and Its Applications

Abstract
Maritime transportation has been, historically, a major factor in economic development and prosperity since it enables trade and contacts between nations. The amount of trade through maritime transport has increased drastically; for example, about 90% of the European Union’s external trade and one-third of its internal trade depend on maritime transport. Major ports, typically, incorporate multiple terminals serving containerships, railways, and other forms of hinterland transportation and require interterminal and intraterminal container transport. Many factors influence the productivity and efficiency of ports and hence their economic viability. Moreover, environmental concerns have been leading to stern regulation that requires ports to reduce, for example, greenhouse gas emissions. Therefore, port authorities need to balance economic and ecological objectives in order to ensure sustainable growth and to remain competitive. Once a containership moors at a container terminal, several quay cranes are assigned to the ship to load/unload the containers to/from the ship. Loading activities require the containers to have been previously made available at the quayside, while unloading ones require the containers to be removed from the quayside. The containers are transported between the quayside and the storage yard by a set of vehicles. This chapter addresses the intraterminal container transport scheduling problem by simultaneously scheduling the loading/unloading activities of quay cranes and the transport (between the quayside and the storage yard) activities of vehicles. In addition, the problem includes vehicles with adjustable travelling speed, a characteristic never considered in this context. For this problem, we propose bi-objective mixed-integer linear programming (MILP) models aiming at minimizing the makespan and the total energy consumption simultaneously. Computational experiments are conducted on benchmark instances that we also propose. The computational results show the effectiveness of the MILP models as well as the impact of considering vehicles with adjustable speed, which can reduce the makespan by up to 16.2% and the total energy consumption by up to 2.5%. Finally, we also show that handling unloading and loading activities simultaneously rather than sequentially (the usual practice rule) can improve the makespan by up to 34.5% and the total energy consumption by up to 18.3%. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

2022

Job-shop scheduling-joint consideration of production, transport, and storage/retrieval systems

Authors
Fontes, DBMM; Homayouni, SM; Resende, MGC;

Publication
JOURNAL OF COMBINATORIAL OPTIMIZATION

Abstract
This paper proposes a new problem by integrating the job shop scheduling, the part feeding, and the automated storage and retrieval problems. These three problems are intertwined and the performance of each of these problems influences and is influenced by the performance of the other problems. We consider a manufacturing environment composed of a set of machines (production system) connected by a transport system and a storage/retrieval system. Jobs are retrieved from storage and delivered to a load/unload area (LU) by the automated storage retrieval system. Then they are transported to and between the machines where their operations are processed on by the transport system. Once all operations of a job are processed, the job is taken back to the LU and then returned to the storage cell. We propose a mixed-integer linear programming (MILP) model that can be solved to optimality for small-sized instances. We also propose a hybrid simulated annealing (HSA) algorithm to find good quality solutions for larger instances. The HSA incorporates a late acceptance hill-climbing algorithm and a multistart strategy to promote both intensification and exploration while decreasing computational requirements. To compute the optimality gap of the HSA solutions, we derive a very fast lower bounding procedure. Computational experiments are conducted on two sets of instances that we also propose. The computational results show the effectiveness of the MILP on small-sized instances as well as the effectiveness, efficiency, and robustness of the HSA on medium and large-sized instances. Furthermore, the computational experiments clearly shown that importance of optimizing the three problems simultaneous. Finally, the importance and relevance of including the storage/retrieval activities are empirically demonstrated as ignoring them leads to wrong and misleading results.

2022

Mitigating Biomass Supply Chain Uncertainty Through Discrete Event Simulation

Authors
Piqueiro, H; de Sousa, JP; Santos, R; Gomes, R;

Publication
Proceedings of the International Conference on Industrial Engineering and Operations Management

Abstract

2022

Ramping up a heuristic procedure for storage location assignment problem with precedence constraints

Authors
Trindade, MAM; Sousa, PSA; Moreira, MRA;

Publication
FLEXIBLE SERVICES AND MANUFACTURING JOURNAL

Abstract
The retail industry is becoming increasingly competitive; as a result, companies are seeking to reduce inefficiencies in their supply chains. One way of increasing the efficiency of operations inside a warehouse is by better allocating products in the available spaces. In this paper, we propose a new heuristic approach to solving the storage location assignment problem (SLAP) considering precedence constraints, in multi-aisle, multi-product picking warehouses. A two-phase heuristic procedure is developed: the products are clustered and assigned to the available spaces. We tested the procedure in the non-perishables warehouse of a real-world Portuguese retail chain, which supplies 191 stores per day. The results show that the new assignment of products allows for an improvement of up to 15% on the distance travelled by the pickers, which implies savings of approximately 477 km per month. This problem is a special case of SLAP since we are dealing with large percentages of non-uniform products. This procedure incorporates four relevant criteria for the allocation decision: the products' similarity, demand and weight, and the distance travelled by the picker. By using a two-phase heuristic method, this study offers companies and academics an alternative and more effective solution for SLAP than the usual methods based on the creation of density zones.

2022

Manufacturing and Management Paradigms, Methods and Tools for Sustainable Industry 4.0-Oriented Manufacturing Systems

Authors
Varela, L; Avila, P; Castro, H; Putnik, GD; Fonseca, LMC; Ferreira, L;

Publication
SUSTAINABILITY

Abstract
In the current Industry 4 [...]

2022

HYBRID GOVERNANCE SYSTEM VALUE PERCEPTION MODEL

Authors
Marchisotti, G; Rodrigues, J; Franca, S; Toledo, R; Castro, H; Alves, C; Putnik, G;

Publication
INTERNATIONAL JOURNAL FOR QUALITY RESEARCH

Abstract
This paper aims to analyze the negative perception about the ability to generate value from a Governance System (GS). A model that would explain the reason for the less positive perception regarding the ability to generate value from the GS of the organizations, from the analysis of the relationship between the constructs Hybridism, GS, Accountability and Perception of Value based on IR, was proposed and validated with structural equation modeling (SEM), based on 658 responses from professionals of Brazilian organizations from the public, private and non-profit sectors. It is suggested that conflicts related to organizational hybridism negatively influence the results orientation of the GS, which in turn influences the imbalance of its Accountability. As a result of the GS's loss of results orientation, and considering the IR capitals in the disclosure of results, there is a negative perception of the GS's ability to add value to the results.

  • 108
  • 386