Solving the forestry logistic problem is involved with multiple short- and long-term operational decisions such as truck routing, inventory management, and scheduling. Although these problems are separately studied in...
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Solving the forestry logistic problem is involved with multiple short- and long-term operational decisions such as truck routing, inventory management, and scheduling. Although these problems are separately studied in the literature, but in many situations, a near-optimal solution of the "comprehensive" problem suffices the managerial needs and directions. In this paper, we consider the forestry logistic and use a simulation-optimization method to reach a near-optimal solution. This method enables us to incorporate different uncertainties such as stochastic travel time and occurrence of external factors. We use real-world data to evaluate our model and measure the complexity of real-world constraints. Copyright (C) 2022 The Authors.
In the fast fashion industry, high delivery frequencies and low lead times are key factors of market competitiveness. To this goal, many companies are evaluating the possibility of opening urban satellites close to re...
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In the fast fashion industry, high delivery frequencies and low lead times are key factors of market competitiveness. To this goal, many companies are evaluating the possibility of opening urban satellites close to retail stores. Urban satellites can assure a number of daily replenishments larger than one at the retail stores. However, opening urban satellites requires expensive capital expenditures and can increase transportation costs. In this paper, we investigate the impact of urban satellites on the service level, inventory and transportation costs of fast fashion supply chains Discrete event simulation is used to assess the value that urban satellites can provide to fast fashion supply chains The application to an Italian retailer case study reveals that the increased transportation and storage costs may be compensated by increased sales as a result of a wider product assortment at the retail stores. The case study simulation results are proposed as possible lessons for other fast fashion last mile distribution systems. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
Deriving a detailed schedule for an unmanned aerial vehicle (UAV) deployment involves a wide range of scheduling problems, where solving them as a whole is intractable. Moreover, uncertainties in operational environme...
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Deriving a detailed schedule for an unmanned aerial vehicle (UAV) deployment involves a wide range of scheduling problems, where solving them as a whole is intractable. Moreover, uncertainties in operational environments of the UAV deployment bring a gap between models assumed for the scheduling problems and an actual system. Motivated by the facts, we propose a conceptual design of a scheduling system for a UAV deployment. Specifically, we first introduce fundamental scheduling problems for UAV deployments and specify dependencies between them. A design for a scheduling system, which sequentially solves the scheduling problems and evaluates the solutions using a simulation model, is then proposed. Finally, a prototype of the scheduling system implemented to demonstrate the feasibility of the design is described. (C) 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
In this paper, the requirements of industrial solutions to plant-wide planning and scheduling problems are discussed. The state-of-the-art algorithms for the coordination of local schedulers are reviewed and a new heu...
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In this paper, the requirements of industrial solutions to plant-wide planning and scheduling problems are discussed. The state-of-the-art algorithms for the coordination of local schedulers are reviewed and a new heuristic method is presented that utilizes the existing distributed scheduling algorithms by considering the coupled due dates and release dates in the distributed schedulers and by penalizing the slacks between the individual optimized schedules and the linking variables iteratively. The performance of the proposed coordination algorithm is evaluated for a prototypical distributed production scheduling problem which consists of two MILP scheduling models. The numerical results show that the proposed coordination scheme is superior compared to fully decentralized and to centralized scheduling algorithms and to other cooperative scheduling methods with respect to solution quality and computational effort.
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