Scheduling
M. Hamid; R. Tavakkoli-Moghaddam; B. Vahedi-Nouri; H. Arbabi
Abstract
Operating rooms (ORs) are among the most influential departments of a hospital that a major portion of its expenditures and revenues originate from it. Due to the limited resources and the presence of different stockholders, effective management, and the optimal planning of this department are challenging. ...
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Operating rooms (ORs) are among the most influential departments of a hospital that a major portion of its expenditures and revenues originate from it. Due to the limited resources and the presence of different stockholders, effective management, and the optimal planning of this department are challenging. This paper develops a mathematical model to address the integrated problem of the operating room and surgical member scheduling with the objective of makespan minimization. In the proposed model, several aspects, including the availability and necessity of surgical members and equipment, and lunch break consideration, are incorporated. Finally, a case study related to an OR department in a general hospital is provided to assess the applicability and performance of the proposed model.
Supply chain management
S. Aliari-Kardehdeh; S. Ayazi-Yazdi; R. Tavakkoli-Moghaddam; H. Farrokhi-Asl
Abstract
This paper considers a dynamic pricing decision problem, in which two different manufacturers compete to distribute substitutable products through a single retailer under two presented scenarios. In the first scenario, the pricing policy is determined via a centralized decision-making, while the second ...
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This paper considers a dynamic pricing decision problem, in which two different manufacturers compete to distribute substitutable products through a single retailer under two presented scenarios. In the first scenario, the pricing policy is determined via a centralized decision-making, while the second scenario manages the policy in a decentralized one. Utilizing the game-theory-based modeling approaches, the pricing decision problem is achieved under with two different structures. Numerical experiments are also given to examine the effects of the presented scenarios and provide further managerial insights on the solutions.
Inventory, logistics, and transportation
H. Farrokhi-Asl; R. Tavakkoli-Moghaddam
Abstract
This paper is an extension of the well-known vehicle routing problem (VRP) consisting of two stages. The first and second stages deal with the vehicle routing and transportation problems, respectively. Waste collection is one of the applications of the considered problem in a real world situation. A ...
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This paper is an extension of the well-known vehicle routing problem (VRP) consisting of two stages. The first and second stages deal with the vehicle routing and transportation problems, respectively. Waste collection is one of the applications of the considered problem in a real world situation. A new mathematical model for this type of the problem is presented that minimizes the waste collection cost and decreases the risk posed to the environment for hazardous wastes transportation simultaneously. According to the NP-hard nature of the problem, a new multi-objective hybrid cultural and genetic algorithm (MOHCG) is proposed to obtain Pareto solutions. A straightforward representation for coding the given model is proposed to help us in reducing the computational time. To validate the proposed algorithm, a number of test problems are conducted and the obtained results are compared with the results of the well-known multi-objective evolutionary algorithm, namely non-dominated sorting genetic algorithm (NSGA-II), with respect to some comparison metrics. Finally, the conclusion is provided.
Supply chain management
F. Mokhtari karchegani; H. Shirouyehzad; R. Tavakkoli-Moghaddam
Abstract
The fast changing and dynamic global business environment require companies to plan their entire supply chain from the raw material supplier to the end customer. In this paper, we design an integrated supply chain including multiple suppliers, multiple factories, multiple distributors, multiple customers, ...
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The fast changing and dynamic global business environment require companies to plan their entire supply chain from the raw material supplier to the end customer. In this paper, we design an integrated supply chain including multiple suppliers, multiple factories, multiple distributors, multiple customers, multiple products, and multiple transportation alternatives. A new multi-objective mixed-integer nonlinear programming model is proposed to deal with this facility location-allocation problem. It considers two conflicting objectives simultaneously, and then the problem is transformed into a multi-objective linear one. The first objective function aims to minimize total losses of the supply chain including raw material purchasing costs, transportation costs and establishment costs of factories and distributions. The second objective function is to minimize the sum deterioration rate of end products and raw materials incurred by transportation alternatives. Finally, the proposed model is solved as a single-objective, mixed-integer, programming model applying the Global Criteria Method. We test their model with numerical example and the results indicate that the proposed model can provide a promising approach to fulfill customer demand and design an efficient supply chain.
M. Niyazi; R. Tavakkoli-Moghaddam
Volume 3, Issue 4 , December 2014, , Pages 41-56
Abstract
Selecting the most appropriate and optimal facility location for a new organization or expansion of an existing location is an important strategic issue. The location, which results in higher economic benefits through increased productivity and good distribution network, is the best location. It is necessary ...
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Selecting the most appropriate and optimal facility location for a new organization or expansion of an existing location is an important strategic issue. The location, which results in higher economic benefits through increased productivity and good distribution network, is the best location. It is necessary to compare the performance characteristics in a decisive way when a choice is to be made from among several alternative facility locations. While the facility location selection problem includes multiple conflicting criteria and a finite set of potential candidate alternatives, different multi-criteria decision making (MCDM) methods can be effectively applied to solve such type of problem. In this paper, we apply three MCDM methods on a facility location selection problem and their relative ranking performances are compared. Because of disagreement in the ranks obtained by the three different MCDM methods, a final ranking method based on REGIME is also proposed to facilitate the decision making process. Then, the results of this study are compared by the results of the same study.
