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This paper addresses an extension of the flexible job shop scheduling problem by considering that jobs need to be moved around the shop-floor by a set of vehicles. Thus, this problem involves assigning each production operation to one of the alternative machines, finding the sequence of operations for each machine, assigning each transport task to one of the vehicles, and finding the sequence of transport tasks for each vehicle, simultaneously. Transportation is usually neglected in the literature and when considered, an unlimited number of vehicles is, typically, assumed. Here, we propose the first mixed integer linear programming model for this problem and show its efficiency at solving small-sized instances to optimality. In addition, and due to the NP-hard nature of the problem, we propose a local search based heuristic that the computational experiments show to be effective, efficient, and robust.
Seyed Mahdi Homayouni; Dalila B. M. M. Fontes. Production and transport scheduling in flexible job shop manufacturing systems. Journal of Global Optimization 2021, 79, 463 -502.
AMA StyleSeyed Mahdi Homayouni, Dalila B. M. M. Fontes. Production and transport scheduling in flexible job shop manufacturing systems. Journal of Global Optimization. 2021; 79 (2):463-502.
Chicago/Turabian StyleSeyed Mahdi Homayouni; Dalila B. M. M. Fontes. 2021. "Production and transport scheduling in flexible job shop manufacturing systems." Journal of Global Optimization 79, no. 2: 463-502.
This work addresses the flexible job shop scheduling problem with transportation (FJSPT), which can be seen as an extension of both the flexible job shop scheduling problem (FJSP) and the job shop scheduling problem with transportation (JSPT). Regarding the former case, the FJSPT additionally considers that the jobs need to be transported to the machines on which they are processed on, while in the latter, the specific machine processing each operation also needs to be decided. The FJSPT is NP‐hard since it extends NP‐hard problems. Good‐quality solutions are efficiently found by an operation‐based multistart biased random key genetic algorithm (BRKGA) coupled with greedy heuristics to select the machine processing each operation and the vehicles transporting the jobs to operations. The proposed approach outperforms state‐of‐the‐art solution approaches since it finds very good quality solutions in a short time. Such solutions are optimal for most problem instances. In addition, the approach is robust, which is a very important characteristic in practical applications. Finally, due to its modular structure, the multistart BRKGA can be easily adapted to solve other similar scheduling problems, as shown in the computational experiments reported in this paper.
S. Mahdi Homayouni; Dalila B. M. M. Fontes; José F. Gonçalves. A multistart biased random key genetic algorithm for the flexible job shop scheduling problem with transportation. International Transactions in Operational Research 2020, 1 .
AMA StyleS. Mahdi Homayouni, Dalila B. M. M. Fontes, José F. Gonçalves. A multistart biased random key genetic algorithm for the flexible job shop scheduling problem with transportation. International Transactions in Operational Research. 2020; ():1.
Chicago/Turabian StyleS. Mahdi Homayouni; Dalila B. M. M. Fontes; José F. Gonçalves. 2020. "A multistart biased random key genetic algorithm for the flexible job shop scheduling problem with transportation." International Transactions in Operational Research , no. : 1.
This paper explores the connections between the classical maximum clique problem and its edge-weighted generalization, the maximum edge weight clique (MEWC) problem. As a result, a new analytic upper bound on the clique number of a graph is obtained and an exact algorithm for solving the MEWC problem is developed. The bound on the clique number is derived using a Lagrangian relaxation of an integer (linear) programming formulation of the MEWC problem. Furthermore, coloring-based bounds on the clique number are used in a novel upper-bounding scheme for the MEWC problem. This scheme is employed within a combinatorial branch-and-bound framework, yielding an exact algorithm for the MEWC problem. Results of computational experiments demonstrate a superior performance of the proposed algorithm compared with existing approaches.
Seyedmohammadhossein Hosseinian; Dalila B. M. M. Fontes; Sergiy Butenko. A Lagrangian Bound on the Clique Number and an Exact Algorithm for the Maximum Edge Weight Clique Problem. INFORMS Journal on Computing 2020, 32, 747 -762.
AMA StyleSeyedmohammadhossein Hosseinian, Dalila B. M. M. Fontes, Sergiy Butenko. A Lagrangian Bound on the Clique Number and an Exact Algorithm for the Maximum Edge Weight Clique Problem. INFORMS Journal on Computing. 2020; 32 (3):747-762.
Chicago/Turabian StyleSeyedmohammadhossein Hosseinian; Dalila B. M. M. Fontes; Sergiy Butenko. 2020. "A Lagrangian Bound on the Clique Number and an Exact Algorithm for the Maximum Edge Weight Clique Problem." INFORMS Journal on Computing 32, no. 3: 747-762.
Luís A.C. Roque; Luís Tiago Paiva; Manuel C.R.M. Fernandes; Dalila Fontes; Fernando A C C Fontes. Layout optimization of an airborne wind energy farm for maximum power generation. Energy Reports 2020, 6, 165 -171.
AMA StyleLuís A.C. Roque, Luís Tiago Paiva, Manuel C.R.M. Fernandes, Dalila Fontes, Fernando A C C Fontes. Layout optimization of an airborne wind energy farm for maximum power generation. Energy Reports. 2020; 6 ():165-171.
Chicago/Turabian StyleLuís A.C. Roque; Luís Tiago Paiva; Manuel C.R.M. Fernandes; Dalila Fontes; Fernando A C C Fontes. 2020. "Layout optimization of an airborne wind energy farm for maximum power generation." Energy Reports 6, no. : 165-171.
Bruno Cretú; Dalila Fontes; Seyed Mahdi Homayouni. A GENETIC ALGORITHM FOR A MULTI-PRODUCT DISTRIBUTION PROBLEM. International Journal for Quality Research 2019, 13, 901 -914.
AMA StyleBruno Cretú, Dalila Fontes, Seyed Mahdi Homayouni. A GENETIC ALGORITHM FOR A MULTI-PRODUCT DISTRIBUTION PROBLEM. International Journal for Quality Research. 2019; 13 (4):901-914.
Chicago/Turabian StyleBruno Cretú; Dalila Fontes; Seyed Mahdi Homayouni. 2019. "A GENETIC ALGORITHM FOR A MULTI-PRODUCT DISTRIBUTION PROBLEM." International Journal for Quality Research 13, no. 4: 901-914.
Maria Teresa Ribeiro Pereira; Elisabete Dias; Dalila Fontes. A MCDA MODEL FOR OLIVE OIL SUPPLIER SELECTION USING MACBETH. International Journal for Quality Research 2019, 13, 849 -862.
AMA StyleMaria Teresa Ribeiro Pereira, Elisabete Dias, Dalila Fontes. A MCDA MODEL FOR OLIVE OIL SUPPLIER SELECTION USING MACBETH. International Journal for Quality Research. 2019; 13 (4):849-862.
Chicago/Turabian StyleMaria Teresa Ribeiro Pereira; Elisabete Dias; Dalila Fontes. 2019. "A MCDA MODEL FOR OLIVE OIL SUPPLIER SELECTION USING MACBETH." International Journal for Quality Research 13, no. 4: 849-862.
Seyed Mahdi Homayouni; Dalila Fontes; Fernando A C C Fontes. A BRKGA for the integrated scheduling problem in FMSs. Proceedings of the Genetic and Evolutionary Computation Conference Companion 2019, 1 .
AMA StyleSeyed Mahdi Homayouni, Dalila Fontes, Fernando A C C Fontes. A BRKGA for the integrated scheduling problem in FMSs. Proceedings of the Genetic and Evolutionary Computation Conference Companion. 2019; ():1.
Chicago/Turabian StyleSeyed Mahdi Homayouni; Dalila Fontes; Fernando A C C Fontes. 2019. "A BRKGA for the integrated scheduling problem in FMSs." Proceedings of the Genetic and Evolutionary Computation Conference Companion , no. : 1.
Goncalo B. Silva; Luis Tiago Paiva; Fernando A C C Fontes. A Path-following Guidance Method for Airborne Wind Energy Systems with Large Domain of Attraction. 2019 American Control Conference (ACC) 2019, 1 .
AMA StyleGoncalo B. Silva, Luis Tiago Paiva, Fernando A C C Fontes. A Path-following Guidance Method for Airborne Wind Energy Systems with Large Domain of Attraction. 2019 American Control Conference (ACC). 2019; ():1.
Chicago/Turabian StyleGoncalo B. Silva; Luis Tiago Paiva; Fernando A C C Fontes. 2019. "A Path-following Guidance Method for Airborne Wind Energy Systems with Large Domain of Attraction." 2019 American Control Conference (ACC) , no. : 1.
We consider the problem of planning the aggregate energy consumption for a set of thermostatically controlled loads for demand response, accounting price forecast trajectory and thermal comfort constraints. We address this as a continuous-time optimal control problem, and analytically characterize the structure of its solution in the general case. In the special case when the price forecast is monotone and the loads have equal dynamics, we show that it is possible to determine the solution in an explicit form. Taking this fact into account, we handle the non-monotone price case by considering several subproblems, each corresponding to a time subinterval where the price function is monotone, and then allocating to each subinterval a fraction of the total energy budget. This way, for each time subinterval, the problem reduces to a simple convex optimization problem with a scalar decision variable, for which a descent direction is also known. The price forecasts for the day-ahead energy market typically have no more than four monotone segments, so the resulting optimization problem can be solved efficiently with modest computational resources.
Fernando A. C. C. Fontes; Abhishek Halder; Jorge Becerril; P. R. Kumar. Optimal Control of Thermostatic Loads for Planning Aggregate Consumption: Characterization of Solution and Explicit Strategies. IEEE Control Systems Letters 2019, 3, 877 -882.
AMA StyleFernando A. C. C. Fontes, Abhishek Halder, Jorge Becerril, P. R. Kumar. Optimal Control of Thermostatic Loads for Planning Aggregate Consumption: Characterization of Solution and Explicit Strategies. IEEE Control Systems Letters. 2019; 3 (4):877-882.
Chicago/Turabian StyleFernando A. C. C. Fontes; Abhishek Halder; Jorge Becerril; P. R. Kumar. 2019. "Optimal Control of Thermostatic Loads for Planning Aggregate Consumption: Characterization of Solution and Explicit Strategies." IEEE Control Systems Letters 3, no. 4: 877-882.
Dalila B.M.M. Fontes; Paulo A. Pereira; Fernando A.C.C. Fontes. A Decision Support System for TV self-promotion Scheduling. International Journal of Advanced Trends in Computer Science and Engineering 2019, 8, 134 -139.
AMA StyleDalila B.M.M. Fontes, Paulo A. Pereira, Fernando A.C.C. Fontes. A Decision Support System for TV self-promotion Scheduling. International Journal of Advanced Trends in Computer Science and Engineering. 2019; 8 (2):134-139.
Chicago/Turabian StyleDalila B.M.M. Fontes; Paulo A. Pereira; Fernando A.C.C. Fontes. 2019. "A Decision Support System for TV self-promotion Scheduling." International Journal of Advanced Trends in Computer Science and Engineering 8, no. 2: 134-139.
In the past few years, important supply chain decisions have captured managerial interest. One of these decisions is the design of the supply chain network incorporating financial considerations, based on the idea that establishment and operating costs have a direct effect on the company’s financial performance. However, works on supply chain network design (SCND) incorporating financial decisions are scarce. In this work, we address a SCND problem in which operational and investment decisions are made in order to maximize the company value, measured by the Economic Value Added, while respecting the usual operational constraints, as well as financial ratios and constraints. This work extends current research by considering debt repayments and new capital entries as decision variables, improving on the calculation of some financial values, as well as introducing infrastructure dynamics; which together lead to greater value creation.
Alexandra Borges; Dalila B. M. M. Fontes; José Fernando Gonçalves. Modeling Supply Chain Network: A Need to Incorporate Financial Considerations. Springer Texts in Business and Economics 2019, 57 -72.
AMA StyleAlexandra Borges, Dalila B. M. M. Fontes, José Fernando Gonçalves. Modeling Supply Chain Network: A Need to Incorporate Financial Considerations. Springer Texts in Business and Economics. 2019; ():57-72.
Chicago/Turabian StyleAlexandra Borges; Dalila B. M. M. Fontes; José Fernando Gonçalves. 2019. "Modeling Supply Chain Network: A Need to Incorporate Financial Considerations." Springer Texts in Business and Economics , no. : 57-72.
This work proposes a multi-criteria decision making model to assist in the choice of a strategic plan for a world-class company. The Balanced Scorecard (BSC) is a support tool of Beyond Budgeting that translates a company’s vision and strategy into a coherent set of performance measures. However, it does not provide help in choosing a strategic plan. The selection of a strategic plan involves multiple goals and objectives that are often conflicting and incommensurable. This paper proposes an integrated Analytic Hierarchy Process-Goal Programming (AHP-GP) approach to select such a plan. This approach comprises two stages. In the first stage, the AHP is used to evaluate the relative importance of the initiatives with respect to financial indicators/KPIs; while in the second stage a GP model incorporating the AHP priority scores is developed. The GP model selects a set of initiatives that maximizes the earnings before interest and taxes (EBIT) and minimizes the Capital Employed (CE). The proposed method was evaluated through a case study.
Dalila B. M. M. Fontes; Maria Teresa Ribeiro Pereira; Márcia Oliveira. Selection of a Strategic Plan Using an Integrated AHP-Goal Programming Approach. Springer Texts in Business and Economics 2019, 125 -141.
AMA StyleDalila B. M. M. Fontes, Maria Teresa Ribeiro Pereira, Márcia Oliveira. Selection of a Strategic Plan Using an Integrated AHP-Goal Programming Approach. Springer Texts in Business and Economics. 2019; ():125-141.
Chicago/Turabian StyleDalila B. M. M. Fontes; Maria Teresa Ribeiro Pereira; Márcia Oliveira. 2019. "Selection of a Strategic Plan Using an Integrated AHP-Goal Programming Approach." Springer Texts in Business and Economics , no. : 125-141.
Seyed Mahdi Homayouni; Dalila Fontes. Joint scheduling of production and transport with alternative job routing in flexible manufacturing systems. INTERNATIONAL CONFERENCE ON “MULTIDIMENSIONAL ROLE OF BASIC SCIENCE IN ADVANCED TECHNOLOGY” ICMBAT 2018 2019, 1 .
AMA StyleSeyed Mahdi Homayouni, Dalila Fontes. Joint scheduling of production and transport with alternative job routing in flexible manufacturing systems. INTERNATIONAL CONFERENCE ON “MULTIDIMENSIONAL ROLE OF BASIC SCIENCE IN ADVANCED TECHNOLOGY” ICMBAT 2018. 2019; ():1.
Chicago/Turabian StyleSeyed Mahdi Homayouni; Dalila Fontes. 2019. "Joint scheduling of production and transport with alternative job routing in flexible manufacturing systems." INTERNATIONAL CONFERENCE ON “MULTIDIMENSIONAL ROLE OF BASIC SCIENCE IN ADVANCED TECHNOLOGY” ICMBAT 2018 , no. : 1.
In this work, we address through model predictive control (MPC) a constrained nonlinear plant described by a continuous-time dynamical model, which naturally leads to a sampled-data control system. The numerical solution of the optimal control problems involved in MPC must utilize, eventually, some form of discretization. Nevertheless, there are several advantages in maintaining a continuous-time model until later stages. One advantage is that we can devise numerical procedures which, by exploiting additional freedom in selecting the discretization points, are more efficient when continuous-time models are used. Here, we discuss an extension to MPC of an Adaptive Mesh Refinement (AMR) algorithm, which has shown to be efficient in solving nonlinear optimal control problems. We derive a sufficient condition that guarantees that an MPC scheme using an adaptive time-mesh refinement algorithm preserves stability.
Luís Tiago Paiva; Fernando A.C.C. Fontes. A Sufficient Condition for Stability of Sampled–data Model Predictive Control using Adaptive Time–mesh Refinement. IFAC-PapersOnLine 2018, 51, 104 -109.
AMA StyleLuís Tiago Paiva, Fernando A.C.C. Fontes. A Sufficient Condition for Stability of Sampled–data Model Predictive Control using Adaptive Time–mesh Refinement. IFAC-PapersOnLine. 2018; 51 (20):104-109.
Chicago/Turabian StyleLuís Tiago Paiva; Fernando A.C.C. Fontes. 2018. "A Sufficient Condition for Stability of Sampled–data Model Predictive Control using Adaptive Time–mesh Refinement." IFAC-PapersOnLine 51, no. 20: 104-109.
Purpose The purpose of this study is to contribute to the existing knowledge about the process of achieving Lean Manufacturing (LM) success. Design/methodology/approach This study uses interpretive structural modeling and captures the opinions of a group of LM experts from a world-class Japanese automobile manufacturer, to map the interrelationships among potential determinants of LM success. This study further uses the data from a survey of 122 leading automobile part manufacturers by performing structural equation modeling to empirically test the research model proposed. Findings Management support and commitment, financial resources availability, information technology competence for LM, human resources management, production process simplicity, supportive culture and supply chain-wide integration are the key determinants that directly or indirectly determine the level of achievement of LM success. Research limitations/implications The determinants of LM success as experienced by Asian automobile manufacturers might be different from determinants of LM success as experienced by Western automobile manufacturers. An interesting direction for future research would be to capture the experts’ inputs from Western automobile manufacturers to complement the findings of this study. Practical implications The practical contribution of this study lays in the development of linkages among various LM success determinants. Utility of the proposed interpretive structural modeling and structural equation modeling methodologies imposing order, direction and significance of the relationships among elements of LM success assumes considerable value to the decision-makers and LM practitioners. Originality/value Building on opinions of a group of LM experts and a case study of leading auto part manufacturers, the present study strives to model the success of LM, a topic that has received little attention to date.
Morteza Ghobakhloo; Masood Fathi; Dalila Fontes; Ng Tan Ching. Modeling lean manufacturing success. Journal of Modelling in Management 2018, 13, 908 -931.
AMA StyleMorteza Ghobakhloo, Masood Fathi, Dalila Fontes, Ng Tan Ching. Modeling lean manufacturing success. Journal of Modelling in Management. 2018; 13 (4):908-931.
Chicago/Turabian StyleMorteza Ghobakhloo; Masood Fathi; Dalila Fontes; Ng Tan Ching. 2018. "Modeling lean manufacturing success." Journal of Modelling in Management 13, no. 4: 908-931.
Abhishek Halder; Xinbo Geng; Fernando A.C.C. Fontes; P.R. Kumar; Le Xie. Optimal power consumption for demand response of thermostatically controlled loads. Optimal Control Applications and Methods 2018, 40, 68 -84.
AMA StyleAbhishek Halder, Xinbo Geng, Fernando A.C.C. Fontes, P.R. Kumar, Le Xie. Optimal power consumption for demand response of thermostatically controlled loads. Optimal Control Applications and Methods. 2018; 40 (1):68-84.
Chicago/Turabian StyleAbhishek Halder; Xinbo Geng; Fernando A.C.C. Fontes; P.R. Kumar; Le Xie. 2018. "Optimal power consumption for demand response of thermostatically controlled loads." Optimal Control Applications and Methods 40, no. 1: 68-84.
Background: This work addresses the maximum edge weight clique problem (MEWC), an important generalization of the well-known maximum clique problem. Methods: The MEWC problem can be used to model applications in many elds including broadband network design, computer vision, pattern recognition, and robotics. We propose a random key genetic algorithm to find good quality solutions for this problem. Computational experiments are reported for a set of benchmark problem instances derived from the DIMACS maximum clique instances. Result: The results obtained show that our algorithm is both effective and efficient, as for most of the problem instances tested we were able to match the best known solutions with very small computational time requirements.
Jose Fernando Goncalves; Fernando A.C.C. Fontes; Dalila B.M.M. Fontes. An Evolutionary Approach to the Maximum Edge Weight Clique Problem. Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 2018, 11, 260 -266.
AMA StyleJose Fernando Goncalves, Fernando A.C.C. Fontes, Dalila B.M.M. Fontes. An Evolutionary Approach to the Maximum Edge Weight Clique Problem. Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering). 2018; 11 (3):260-266.
Chicago/Turabian StyleJose Fernando Goncalves; Fernando A.C.C. Fontes; Dalila B.M.M. Fontes. 2018. "An Evolutionary Approach to the Maximum Edge Weight Clique Problem." Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) 11, no. 3: 260-266.
In this article we investigate the problem of generating electricity through an underwater kite power system (UKPS). For this problem, we develop the dynamical model for the UKPS and we formulate an optimal control problem to devise the trajectories and controls of the kite that maximize the total energy produced in a given time interval. This is a highly nonlinear problem for which the optimization is challenging. We also develop a numerical solution scheme for the optimal control problem based on direct methods and on adaptive time-mesh refinement. We report results that show that the problem can be quickly solved with a high level of accuracy when using our adaptive mesh refinement strategy. The results provide a set of output power values for different design choices and confirm that electrical energy that can be produced with such device.
Luís Tiago Paiva; Fernando A. C. C. Fontes. Optimal electric power generation with underwater kite systems. Computing 2018, 100, 1137 -1153.
AMA StyleLuís Tiago Paiva, Fernando A. C. C. Fontes. Optimal electric power generation with underwater kite systems. Computing. 2018; 100 (11):1137-1153.
Chicago/Turabian StyleLuís Tiago Paiva; Fernando A. C. C. Fontes. 2018. "Optimal electric power generation with underwater kite systems." Computing 100, no. 11: 1137-1153.
This work proposes an integrated formulation for the joint production and transportation scheduling problem in flexible manufacturing environments. In this type of systems, parts (jobs) need to be moved around as the production operations required involve different machines. The transportation of the parts is typically done by a limited number of Automatic Guided Vehicles (AGVs). Therefore, machine scheduling and AGV scheduling are two interrelated problems that need to be addressed simultaneously. The joint production and transportation scheduling problem is formulated as a novel mixed integer linear programming model. The modeling approach proposed makes use of two sets of chained decisions, one for the machine and another for the AGVs, which are inter-connected through the completion time constraints both for machine operations and transportation tasks. The computational experiments on benchmark problem instances using a commercial software (Gurobi) show the efficiency of the modeling approach in finding optimal solutions.
Dalila B. M. M. Fontes; Seyed Mahdi Homayouni. Joint production and transportation scheduling in flexible manufacturing systems. Journal of Global Optimization 2018, 74, 879 -908.
AMA StyleDalila B. M. M. Fontes, Seyed Mahdi Homayouni. Joint production and transportation scheduling in flexible manufacturing systems. Journal of Global Optimization. 2018; 74 (4):879-908.
Chicago/Turabian StyleDalila B. M. M. Fontes; Seyed Mahdi Homayouni. 2018. "Joint production and transportation scheduling in flexible manufacturing systems." Journal of Global Optimization 74, no. 4: 879-908.
In the context of continuous–time control systems, we address the problem of guaranteeing that the constraints imposed along the trajectory are in fact satisfied for all times. The problem is relevant and non–trivial in situations in which a continuous–time internal representation of the system is used with a digital device, such as in sampled–data model–based control, in an optimal control solver, or in sampled-data model predictive control. In this paper, we establish a condition that when verified on a finite set of time instants (using limited computational power) can guarantee that the trajectory constraints are satisfied on an uncountable set of times. The case of constrained optimal control problems is further explored here. We develop an algorithm for the numerical solution of constrained nonlinear optimal control problems that combines a guaranteed constraint satisfaction strategy with an adaptive mesh refinement strategy.
Fernando A. C. C. Fontes; Luis Tiago Paiva. Guaranteed Constraint Satisfaction in Continuous-Time Control Problems. IEEE Control Systems Letters 2018, 3, 13 -18.
AMA StyleFernando A. C. C. Fontes, Luis Tiago Paiva. Guaranteed Constraint Satisfaction in Continuous-Time Control Problems. IEEE Control Systems Letters. 2018; 3 (1):13-18.
Chicago/Turabian StyleFernando A. C. C. Fontes; Luis Tiago Paiva. 2018. "Guaranteed Constraint Satisfaction in Continuous-Time Control Problems." IEEE Control Systems Letters 3, no. 1: 13-18.