supply chain management
Fatemeh Arjmandi; Parvaneh Samouei
Abstract
Planning and scheduling operating rooms and required equipment is very important for hospital managers from the perspective of cost, social, and health principles. Because operating rooms are one of the sources of income for hospitals that can provide the services needed by emergency patients who arrive ...
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Planning and scheduling operating rooms and required equipment is very important for hospital managers from the perspective of cost, social, and health principles. Because operating rooms are one of the sources of income for hospitals that can provide the services needed by emergency patients who arrive randomly and elective patients whose surgery is preplanned. Since some tools used in operating rooms need to be sterilized each time, and in the real world, due to various reasons such as the physical condition of each patient, the duration of surgeries is uncertain, in this research, as well as considering the uncertainty of surgery times for emergency and elective patients, a robust scenario-based integrated mathematical model with two objective functions is presented. In this model, in addition to minimizing the cost of operating rooms, sterile section, and penalties for delay in surgery, the competition time of the last operation is minimized. Solving several problems and different sensitivity analyses confirmed the validation of the presented model from the viewpoint of the hospital managers.
Introduction
The healthcare system is one of the most important topics that has attracted the attention of researchers and hospital managers. Two significant elements of healthcare systems are patients and hospitals, and their planning and scheduling are necessary for providing better services. Hospital managers aim to minimize costs or maximize profits while considering service times. Operating rooms are often the most critical sections of the hospital. Since life and death issues are at stake in the operating rooms, even the slightest delay or lack of resources can endanger human lives. Therefore, careful planning and scheduling of operating rooms and their resources is especially important. Additionally, to prevent potential hospital infections, the sterilization of reusable medical instruments is essential for every operation. Furthermore, patients can be broadly categorized into two groups: emergency patients who arrive randomly, and elective patients whose surgeries are preplanned. Planning and scheduling operating rooms, along with the required equipment, is of utmost importance for hospital managers, taking into account cost, social factors, and health considerations. Some items used in operating rooms need to be sterilized after each use, which incurs both time and cost.
Methodology
Due to high fluctuations of the duration of surgery, the different condition of each patient, and in order to get as close as possible to the real conditions, the duration of each surgery is considered uncertain. In this research, in addition to considering selected patients, considering the uncertainty of the duration of surgery, emergency patients have also been investigated, and dealing with uncertainties, the robust optimization approach is used. This approach is stable against changes, and minimizes the fluctuation of changes and maintains optimal and feasible. Therefore, in this research, as well as considering the uncertainty of surgery times for emergency and elective patients, a robust scenario-based integrated mathematical model with two objective functions is presented. In this model, in addition to minimizing the cost of operating rooms, sterile section, and penalties for delay in surgery, the competition time of the last operation is minimized. There are costs for performing elective and emergency operations, and in order to give priority to emergency patients, the cost of performing the operation of these patients is lower than the cost of performing elective operations surgeries of emergency patients, such as those injured in accidents, must be performed as soon as possible and these patients should be paid less. Also, for emergency patients, a maximum waiting time is considered, which they should not wait more than it. Obviously, surgeries that cannot be scheduled during the working hours of the operating room are postponed. Every patient needs a number of reusable medical tools that require sterilization. The sterile duration of reusable tools and the capacity of each sterile machine are known.
There are various techniques for solving multi-objective problems, one of which is the epsilon constraint method. In this method, one of the objective functions is considered as the main objective function and other objective functions are applied as constraints to the problem. Various developments for the epsilon constraint method have been presented to make it more efficient, among which we can mention the Augmented Epsilon Constrain (AEC) method. Moreover, in order to solve the bi-objective integrated mathematical model, Mulvey's robust method is implemented on the model, and its validation is carried out in the GAMS software with the AEC method.
Results and Conclusion
Different sensitivities all confirm the validity and accuracy of the model from the point of view of hospital managers. According to the obtained results, the changes of the three parameters of surgery delay cost, duration of surgery and sterile duration times have more effects on the both objective functions of the mathematical model than other parameters of the problem. Furthermore, the obtained results show that the first objective function, which includes the total cost, will have the highest value when the delay cost parameters and the duration of the surgical operations increase. For the second objective function, which shows the complete time of the last operation, the most challenging situation occurs when the parameters of the duration of surgical operations and the sterile duration increase. Therefore, the most ideal situation from the point of view of the hospital manager is to reduce all three parameters, which will reduce, the total cost and the completion time of the last operation; Moreover, the results show, the separate costs of planning and scheduling of the operating room and the sterile department are more than when the planning and scheduling of the operating rooms and the sterile department were examined in an integrated manner. The results of this research can be used for the integrated planning and scheduling of the operating rooms and sterilization department in all hospitals as a suitable management tool.
Ehsan Yadegari; Akbar Alem Tabriz; Mostafa Zandieh
Abstract
Over the past decade, due to environmental laws and the competitive environment, development of an effective tactical plan for efficient and integrated supply chain and considering the responsibility of organizations to collect defective goods seems impossible. In this paper a mixed-integer linear programming ...
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Over the past decade, due to environmental laws and the competitive environment, development of an effective tactical plan for efficient and integrated supply chain and considering the responsibility of organizations to collect defective goods seems impossible. In this paper a mixed-integer linear programming is considered to mathematically model the essentially five stages along our supply chain network: suppliers, manufacturers, DCs, customers, and Dismantlers.Delivers raw materials from suppliers to factories and then through distribution centers, delivering the final product to customers. On the other hand, it simultaneously collects recycled goods from customers and enters the cycle of safe reconstruction or destruction.The aim of this model is minimizing the costs of establishing facilities at potential points as well as the optimal flow of materials in the network layers. Since the problem is NP-hard, to solve it, the cloud theory based simulated annealing algorithm has been used. We also used the tree-covering method to show the answer, which uses fewer arrays than other methods in the literature. To analyze the accuracy and speed of the proposed algorithm, we compared its performance with the genetic and simulated annealing algorithm. The results show that the cost function in the cloud-based refrigeration simulation algorithm provides more accurate answers than both algorithms studied in the literature. The results show that the cost function in the cloud-based simulated annealing algorithm provides more accurate answers than both algorithms studied in the literature. Also, in terms of convergence rate criterion, the proposed method has better position than the genetic algorithm, but it is not significantly different from simulated annealing algorithm.
Javad Behnamian; Mohammad Mehdi Bashar
Abstract
Cooperation in supply chain, due to conflicts in goals, is one the most important topics in SCM. With cooperation, players in supply chain echelons have agree with each other to play in supply chain game as a whole. To reach highest profit in the whole supply chain in cooperation condition, using game ...
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Cooperation in supply chain, due to conflicts in goals, is one the most important topics in SCM. With cooperation, players in supply chain echelons have agree with each other to play in supply chain game as a whole. To reach highest profit in the whole supply chain in cooperation condition, using game theory concept and side-contract of partnership in profits and considering marketing cost between manufacture and retailer, a cooperative multi-echelon supply chain is designed. In this paper, for the first time, mathematical modeling in fuzzy environment is presented, taking into account a discount that is approximated to the actual situation where the marketing cost is considered as triangular fuzzy number. The proposed model has been solved using Genetic algorithm (GA), simulated annealing algorithm (SA) and a hybrid algorithm based on GA-SA, for some random examples, and the model has been validated using GAMS software.
modeling and simulation
Navid Nadimi; Abbas Toloei Eshlaghy; Mohammad Ali Afshar kazemi
Abstract
With the tremendous progress in communications in the world, the transformation andbehavior of mobile operators and their digitalization, which in the past were onlyservice providers, as well as the creation of different experiences for customers, isinevitable.The purpose of this study is to create a ...
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With the tremendous progress in communications in the world, the transformation andbehavior of mobile operators and their digitalization, which in the past were onlyservice providers, as well as the creation of different experiences for customers, isinevitable.The purpose of this study is to create a hybrid simulation of systemdynamics and agent based model in order to analyze the revenue of the first operator inthe country to enter the field of digital platform and development of nativeapplications. Using the model proposed, first operators need to enter the digital areaand produce native applications was expressed. Then, the factors that affect the mobileecosystem which, affect the production of applications and the development ofrequired platforms were described. By utilizing hybrid simulation of system dynamicsand agent based modeling, the income of mobile operator in entering and not enteringthe digital arena and producing native applications were examined. The results showthat with the entry of the operator into the field of production of native applicationsand the adoption of digital approach, consumers tended to use more data services, butdue to different tariffs for data and voice, the operator's income up to 2 Next years willnot change much.
Mohsen Jami; Hamidreza Izadbakhsh; Alireza Arshadi Khamseh
Abstract
In the management of the blood supply chain network, the existence of a coherent and accurate program can help increase the efficiency and effectiveness of the network. This research presents an integrated mathematical model to minimize network costs and blood delivery time, especially in crisis conditions. ...
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In the management of the blood supply chain network, the existence of a coherent and accurate program can help increase the efficiency and effectiveness of the network. This research presents an integrated mathematical model to minimize network costs and blood delivery time, especially in crisis conditions. The model incorporates various factors such as the concentration of blood collection, processing, and distribution sites in facilities, emergency transportation, pollution, route traffic (which can cause delivery delays), blood type substitution, and supporter facilities to ensure timely and sufficient blood supply. Additionally, the model considers decisions related to the location of permanent and temporary facilities at three blood collection, processing, and distribution sites, as well as addressing blood shortages. The proposed model was solved for several problems using the Augmented epsilon-constraint method. The results demonstrate that deploying advanced processing equipment in field hospitals, concentrating sites in facilities, and implementing blood type substitution significantly improve network efficiency. Therefore, managers and decision-makers can utilize these proposed approaches to optimize the blood supply chain network, resulting in minimized network costs and blood delivery time.IntroductionOne of the most important aspects of human life is health, which has a significant impact on other aspects of life. In this study, a two-objective mathematical programming model is proposed to integrate the blood supply chain network for both normal and crisis conditions at three levels: blood collection, processing and storage, and blood distribution. The proposed two-objective mathematical model simultaneously minimizes network costs and response time. The model is solved using the augmented epsilon-constraint method. To enhance the responsiveness to patient demand in healthcare facilities and address shortages, the model considers the concentration of levels (collection, processing and storage, and distribution of blood to patients) in facilities, blood type substitution, and supporter facilities. In blood type substitution, not every blood type can be used for every patient. Among several compatible blood groups, there is a prioritization for blood type substitution, allowing for an optimal allocation of blood groups based on the specific needs.Materials and MethodsIn this research, a two-objective mathematical programming model is proposed to design an integrated blood supply chain network at three levels: collection, processing, and distribution of blood in crisis conditions. The proposed model determines decisions related to the number and location of all permanent and temporary facilities at the three levels of blood collection, processing, and distribution, the quantity of blood collection, processing, and distribution, inventory levels and allocation, amount of blood substitution, and transportation method considering traffic conditions. Achieving an optimal solution for the developed two-objective model, which minimizes both objective functions simultaneously while considering the trade-off between the objective functions, is not feasible. Therefore, multi-objective solution methods can be used to solve problems considering the trade-off between objectives. In this research, the augmented epsilon-constraint method is employed to solve the proposed two-objective mathematical model. In this method, all objective functions, except one, are transformed into constraints and assigned weights. By defining an upper bound for the transformed objective functions, they are transformed into constraints and solved.Discussion and ResultsAlthough the two-objective mathematical model is transformed into a single-objective model using the augmented epsilon-constraint method, this approach can still yield Pareto optimal points. Therefore, managers and decision-makers can create a balanced blood supply chain network considering the importance of costs and blood delivery time. Sensitivity analysis was conducted to examine the effect of changes in the weights of the objective functions and the blood referral rate (RD parameter) on the values of the objective functions for three numerical examples. With changes in the weights of the objective functions relative to each other, the trend of changes in the values of the first and second objective functions for all three solved problems is similar. Specifically, when reducing the weight of the first objective function from 0.9 to 0.1, the values of the first objective function increase, while the values of the second objective function decrease when the weight of the second objective function increases from 0.1 to 0.9. The total amount of processed blood in field hospitals and main blood centers was compared for equal weights and time periods for the three problems. Additionally, the amount of processed blood in field hospitals is significantly higher than in main blood centers. This indicates that eliminating the cost and time of blood transfer in field hospitals (due to the concentration of blood collection, processing, and distribution levels) results in an increased amount of processed blood compared to main blood centers (single-level facilities), ultimately leading to a reduction in network costs.ConclusionThis study presents a two-objective mathematical model for the blood supply chain network, integrating pre- and post-crisis conditions. Decisions are proposed for the deployment of four types of facilities, including temporary blood collection centers, field hospitals, main blood centers, and treatment centers, at three levels of blood collection, processing, and distribution. Additionally, inventory, allocation, blood group substitution, blood shortage, transportation mode, and route traffic (delivery delays) are considered for four 24-hour periods in the model. For the first time in this field, knowledge of concentration levels in facilities is utilized, with simultaneous existence of the three levels of blood collection, processing, and distribution in field hospitals. This problem is formulated in a mixed-integer linear programming model with two objective functions aiming to minimize system costs and blood delivery time. The proposed model is solved using the augmented epsilon-constraint evolution method. Sensitivity analysis is conducted for the weights of the objective functions, and additional experiments (RD parameter) are performed. The sensitivity analysis on the weights of the objective functions reveals that reducing the weight of the first objective function leads to a decrease in blood delivery time, while increasing the weight of the second objective function results in an increase in network costs. The investigation of the impact of reducing the amount of additional testing (RD parameter) on the values of the objective functions confirms that advanced equipment at the processing sites of field hospitals reduces network costs and blood delivery time.
Abstract
. The control and planning of operating rooms have became more and more important for hospital managers. Nowadays, the operating rooms, as key resources, often lead to a great time waste. So, appropriate scheduling of operations in order to increase the efficiency of the operating rooms, are significant ...
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. The control and planning of operating rooms have became more and more important for hospital managers. Nowadays, the operating rooms, as key resources, often lead to a great time waste. So, appropriate scheduling of operations in order to increase the efficiency of the operating rooms, are significant research topics in medical care. In this study, a new linear programming model has been developed for the assignment of patients to the operating rooms. Since the duration of surgical procedure is a stochastic parameter, in this paper a two-stage stochastic programming model has been presented in addition the deterministic model. These presented modelssimultaneously investigate the scheduling of surgeries and allocating them to the surgery rooms. The aim of this study is to minimize the cost of assigning patients to unspecialized rooms and reduce the cost of doctors’ idle time per working shifts by taking into account the constraints. The suggested models were applied for the surgery department of Ghaem hospital of Mashhad and solved by ILOG CPLEX 12.6.1 Microsoft Visual Studio environment. The results show that the deterministic proposed model increases the average efficiency of hospital to 38.275% and the stochastic model increases the average efficiency to 85.32%.
Seyed Hossein Razavi Hajiagha; Hadi Akrami; Shide Sadat Hashemi
Volume 11, Issue 31 , January 2014, , Pages 35-53
Abstract
Master production scheduling is a midterm phase in planning which translates the long term aggregate production planning to a plan which determines the scheduling and magnitude of different products production. This problem requires investigating a wide range of parameters about demand, manufacturing ...
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Master production scheduling is a midterm phase in planning which translates the long term aggregate production planning to a plan which determines the scheduling and magnitude of different products production. This problem requires investigating a wide range of parameters about demand, manufacturing resource usage and costs. Uncertainty is an intrinsic characteristic of these parameters. In this paper, a model is developed for master production scheduling under uncertainty where demands are considered as stochastic variables, while cost and utilization parameters are expressed as fuzzy numbers. A hybrid approach is also proposed to solve the extended model. The application of the proposed method is examined in a numerical example.
Magbsood Amiri
Volume 2, Issue 7 , December 2004, , Pages 37-55
Abstract
One of the most important issues in inventory control is determination of the reorder point. Defining parameters of this point are usually in forms of crisp or probability. In this article the parameters are considered as fuzzy numbers because of ambiguities in the real world. Then reorder point ...
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One of the most important issues in inventory control is determination of the reorder point. Defining parameters of this point are usually in forms of crisp or probability. In this article the parameters are considered as fuzzy numbers because of ambiguities in the real world. Then reorder point value is calculated using a cut concept extension principle fuzzy arithmetic and fuzzy trapezoidal numbers. Finally concluding remarks are given.
Ali Khatami Firoozabadi; Hossein Mohebbi; Mohammad Zarei Mahmoodabadi
Volume 8, Issue 21 , June 2011, , Pages 39-61
Abstract
Shortest-path problem is one of the well-known optimization problems that has been studied by many scientists in recent years. Applications of this problem such as transportation and communication are generally solved by Dijkstra's Algorithm (Labeling). In this paper, two separate scientific fields, ...
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Shortest-path problem is one of the well-known optimization problems that has been studied by many scientists in recent years. Applications of this problem such as transportation and communication are generally solved by Dijkstra's Algorithm (Labeling). In this paper, two separate scientific fields, electronics and operation research have been linked to each other and a new algorithm has been created for to find the optimization solution of a shortest- path problem by using electric networks and rules. The proposed algorithm can solve the shortest-path problem in directed graphs and no order ones, and also can solve the longest path problems in directed graphs.
In this algorithm, electrical network are used in a way that the resistance value of each branch is equal to each edge weights in the shortest-path problems. Then with using Ohm Law and Kirchhaffs Voltage Law (KVL), the current in each circuit cycle is calculated. Then the branches that contain the most passing current are specified, and according to Ohm’s Law, has the lowest resistance or weight. Thus, the shortest path in the network is achieved. Advantage of this algorithm is faster convergence to the answer and less computing time than the conventional method, especially in networks with more nods. The mentioned algorithm has been described for three examples.
mohammad rahim ramazanian; mohammad hasan gholizadeh; shiva shaban
Volume 11, Issue 29 , July 2013, , Pages 41-59
Abstract
In this paper, based on the background of cost-oriented assembly line balancing problems, a novel mathematical model for scheduling and balancing the assembly line is offered that with the combination of task sequence-dependent setup time, parallel stations and resource constraint, minimizes ...
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In this paper, based on the background of cost-oriented assembly line balancing problems, a novel mathematical model for scheduling and balancing the assembly line is offered that with the combination of task sequence-dependent setup time, parallel stations and resource constraint, minimizes the operational and investment costs of assembly system.
Due to the complexity of the problem, the equations have been proposed to reduce the number of variables of the model, and to achieve the optimal solution in reasonable time using exact algorithms. To clarify and explain the features of the model a numerical example have been used. Also the solutions obtained from model in several examples, have been analyzed using different indexes, and results indicative of appropriate performance of the model
alireza alinezhad; kavoos simiari
Volume 11, Issue 28 , April 2013, , Pages 41-60
Abstract
One of the important issues in project management is project portfolio selection. Issue of project selection and related activities is one of the important activities in most of organizations, especially contract companies and developing project centered companies. Issue of project choosing is a periodical ...
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One of the important issues in project management is project portfolio selection. Issue of project selection and related activities is one of the important activities in most of organizations, especially contract companies and developing project centered companies. Issue of project choosing is a periodical activity for choosing suitable portfolio from suggested projects or organizational in process projects which enforce organizational goals in a desirable manner , without spending additional sources or / and neglecting other limitations. . In project portfolio selection, the most important issue which bring up is that this portfolio should conclude which projects. As much as project portfolio selection be more advisable, fulfilment of organization duties would be more probable. In choosing this combination, distinguishing opportunities, assessing amount of project cooperation with goals and organization structure and expenses, profit analysis and project risks has a great importance.
In this research has been used from qualitative and quantitative assimilated approach for project portfolio selection. In a way that at first we use DEMATEL (Decision Making Trial and Evaluation Laboratory) method to selection criteria and then with use Data Envelopment Analysis and criteria that selected in previous stage, calculate the efficiency for each project and rank all of them
Abolfazl Kazemi; Pasha Pasha Fakhori; Ali Shakourloo,
Volume 13, Issue 38 , October 2015, , Pages 41-69
Abstract
Accurate scheduling of project is one of the main fundamentals and essential success factors of the project management and also accordance of planning and implementation is considered as the main subject of project management. In this paper, it is tried to propose a practical and suitable system in order ...
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Accurate scheduling of project is one of the main fundamentals and essential success factors of the project management and also accordance of planning and implementation is considered as the main subject of project management. In this paper, it is tried to propose a practical and suitable system in order to schedule various projects more accurately. Currently Program Evaluation and Review Technique (PERT) is used extensively for management of large- scaled projects. In traditional methods of PERT technique, implementation time of each activity is obtained in the form of definite figures or through Beta Distribution but in the real world; it is very hard to estimate the practical implementation time of each activity in an accurate way. By using fuzzy logic in order to overcome the problems related to uncertainty, fuzzy expert system is designed which many limitations and factors affecting the project completion time have been considered in this article. In this regard, output and input parameters of the system have been acquired by questionnaire and validation of the results has been analyzed. The obtained results indicate high power of the system in controlling different situations affecting the project completion time.
M. Momeni; A. Atashsooz
Volume 2, Issue 4 , March 2004, , Pages 41-74
Abstract
QFD starts with the house of quality (HOQ) which is a planning matrix translating the customer needs into measurable product technical requirements (PTRs). As with any other tool the quantum of benefits obtained from the use of QFD is proportional to the effectiveness of its use. A robust analytic method ...
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QFD starts with the house of quality (HOQ) which is a planning matrix translating the customer needs into measurable product technical requirements (PTRs). As with any other tool the quantum of benefits obtained from the use of QFD is proportional to the effectiveness of its use. A robust analytic method should consider the interrelationships among customer needs and PTRs while determining the importance levels of PTRs in the HOQ. This research employs the analytic network process (ANP) to fulfill this requirement. Furthermore the proposed analytic procedure should take into account the multi objective nature of the problem and thus incorporate other goals such as resource limitation extendibility and manufacturability of software technical requirements (STRs). This research presents a zero one goal programming methodology that includes importance levels of STRs derived using the ANP human resource limitation extendibility level and manufacturability level goals to determine the STRs to be considered in designing the software. Finally with regard to the result of the implemented model it is proposed some solutions for the company to reach a better software design to enhance the customer satisfaction.
Noor Mohammad Yaghubi; Roghayeh Sadat Kuchakzadeh
Volume 3, Issue 9 , June 2005, , Pages 41-56
Abstract
The reasons of organizations success of third millennium in competitiopns are motion toward knowledge management and knowledge base a supportive role of IT eases the process of knowledge management a makes it as a competitive advantage. Accordingly the authors has describe the supportive factors of IT ...
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The reasons of organizations success of third millennium in competitiopns are motion toward knowledge management and knowledge base a supportive role of IT eases the process of knowledge management a makes it as a competitive advantage. Accordingly the authors has describe the supportive factors of IT and its use in knowledge management process in this paper first come the knowledge management and TI discussions a then the role of IT in knowledge management is added. After that the parameters which have an important influence on knowledge management are stated. It supporters in making knowledge process in another theme discussion of the study and finally the role of it as a support and ease knowledge management process has been studied.
Mahmood Alborzi; Seyed Amir Reza Abtahi
Volume 4, Issue 13 , June 2006, , Pages 41-66
Abstract
This paper uses neural network to predict corrosion rate. Corrosion can not modeled easily, because of wide range of causes either known or unknown. In mechanistic approach, physical, chemical and electrochemical reactions and processes are considered to model and predict. ...
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This paper uses neural network to predict corrosion rate. Corrosion can not modeled easily, because of wide range of causes either known or unknown. In mechanistic approach, physical, chemical and electrochemical reactions and processes are considered to model and predict. But as stated before this models are not practically successful in prediction because of unknown parameters.
This paper uses genetic optimized neural network to predict corrosion rate. Among different neural networks, multi layer neural network with gradient descent learning algorithm has been selected. After developing the network, learning process has been done, using an oil refinery'S data. Then evaluation and test have been performed. After preparing the network Garson's algorithm and sensitivity analysis have been used for knowledge extraction.
According to results, neural network approach can predict corrosion rate with acceptable correlation coefficient (R) and mean squared error (MSE). Sensitivity analysis depicts the strength of each oil parameter influence on corrosion rate. Among these results, salt and sulphur are the most affecting parameters in corrosion rate.
Seddigheh Khorshid
Volume 8, Issue 18 , September 2010, , Pages 41-69
Abstract
Globalization and competitiveness have undergone earthquakes, tremors and aftershocks on global manufacturing environment, that have forced manufacturing organizations to restructure and change way of doing their business. Furthermore, manufacturing organizations have realized that agility is essential ...
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Globalization and competitiveness have undergone earthquakes, tremors and aftershocks on global manufacturing environment, that have forced manufacturing organizations to restructure and change way of doing their business. Furthermore, manufacturing organizations have realized that agility is essential to survive and competition. But, the ability to build agile manufacturing companies has developed less than anticipated. Because, manufacturing organization managers faced with this problem that how much agility an organization currently possess, determining how much is needed. In this article, an hierarchical model based on fuzzy weighted average technique in order to support managers' decisions for building manufacturing agile is Presented. This model can capture the vague and uncertainty of agility indicators, and the expert's knowledge and judgment. The model was performed in Khozestan's Steel industry.
Mehdi Yazdani; Mostafa Zandieh; Reza Tavakkoli-Moghaddam
Volume 12, Issue 33 , July 2015, , Pages 43-74
Abstract
In this paper, the dual-resource constrained flexible job-shop scheduling problem (DRCFJSP) with objective of minimizing the makespan is investigated. Under studied problem is NP-hard and mainly includes three sub-problems. The first one is to assign each operation to a machine out ...
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In this paper, the dual-resource constrained flexible job-shop scheduling problem (DRCFJSP) with objective of minimizing the makespan is investigated. Under studied problem is NP-hard and mainly includes three sub-problems. The first one is to assign each operation to a machine out of a set of capable machines, the second one is to determine a worker among a set of skilled workers for processing each operation on the selected machine and the third one deals with sequencing the assigned operations on the machines considering workers in order to optimize the performance measure. In this paper, we provide a mathematical model for this problem and then propose a hybrid meta-heuristic algorithm for solving the problem. The proposed hybrid algorithm uses variable neighborhood search and simulated annealing algorithms to search in the solution space. Computational study with randomly generated test problems is performed to evaluate the performance of the proposed algorithm. The results show the proposed algorithms are effective approaches for solving the DRCFJSP.
S.M. Ali Khatami Firouzabadi; Amin Vafadar Nikjoo
Volume 10, Issue 27 , January 2012, , Pages 44-67
Abstract
In this research, we use Artificial Bee Colony (ABC) algorithm tosolve cell to switch assignment problem (CTSAP) that is NP-hard. InCTSAP, there are cells and switches in which cells locations arepredetermined. The objective of problem is optimal assigning of cellsto switches with minimum cost. Here, ...
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In this research, we use Artificial Bee Colony (ABC) algorithm tosolve cell to switch assignment problem (CTSAP) that is NP-hard. InCTSAP, there are cells and switches in which cells locations arepredetermined. The objective of problem is optimal assigning of cellsto switches with minimum cost. Here, we have two kinds of costs,handoff and cabling costs. Call handling capacity for every switchesare given and equal. The model of our work is single homed that iseach cell must connect to only one switch. The mathematical model isbinary and nonlinear.The program is coded by MATLAB 7.8.0 (R2009a). After estimatingparameters values of model, approving performance accuracy of codeand adjusting control parameters, the efficiency of algorithm bydetermining experimental problems compared to Ant ColonyOptimization (ACO) that is one of the best for solving this problem.Results show satisfactory performance of ABC algorithm
Sh. Zahedi; N. Yaghoobi
Volume 2, Issue 6 , September 2004, , Pages 45-64
Maghsoud Amiri; Mohsen Rahimi Mazrae shahi; Hamid Taboli
Volume 9, Issue 24 , March 2012, , Pages 45-65
Abstract
This article suggests a new method for solving multi-criteria decision making issues. The method has been designed by simple but rational mathematical logic based on a specific geometric definition of the options. Understandable content as well as algorithm simplicity and simplified process are the rich ...
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This article suggests a new method for solving multi-criteria decision making issues. The method has been designed by simple but rational mathematical logic based on a specific geometric definition of the options. Understandable content as well as algorithm simplicity and simplified process are the rich standing points of the approach. Such problems have always had a brand-new geometric approach whilst the calculations involved in this method are benefiting from the lack of complex and complicated steps and the essential patronized path. Categorizing the enriched method's significances, we may finally come up with the availability of graphical model provided for the users. The users are properly enabled to enlighten presenting a geometric logic.
Reza Esmaeilpour; Adel Azar; Mohammad ShahMohammadi
Abstract
Nowadays many organizations involved in environmental, social and economic concerns and measure supplier performance on the fields; including the effect that "corporate social responsibility" could have on the suppliers’ selection. The aim of this study is determine of a model to selection of suppliers ...
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Nowadays many organizations involved in environmental, social and economic concerns and measure supplier performance on the fields; including the effect that "corporate social responsibility" could have on the suppliers’ selection. The aim of this study is determine of a model to selection of suppliers based on corporate social responsibility. By a review of research literature and obtaining the opinion of experts, the issues were identified in the 5 dimensions (organizational commitment, employee, commitment to society and citizenship, moral commitments, environmental commitments) and 17 indicators. Then the matrix structured questionnaire was developed to determine the intermediate relationship of these indicators. Questionnaire's obtained data analyses using ISM so it was traced 6 levels in an interactive network that indicator "focus on sustainable development" was at the highest level. Also, influence and dependence of the indicators relative to each other on the matrix influence-dependence was evaluated. The most influential indicator in the matrix influence-dependence is "Providing relevant training in CSR to the suppliers”; so the implementation of Corporate Social Responsibility in the selection of suppliers depends on their training and to be with this attitude, long-term plans would be design on the basis of social responsibility training specifically for suppliers
Seyed Mohammad Aarabi; Mohsen Adabi Firozjaee
Volume 3, Issue 10 , September 2005, , Pages 47-67
Abstract
In spite of spending too much expenses for acquiring and importing technology in most of the developing countries. And even in most organizations. It can be observed that these technologies are not well absorbed and the technology does not act as the engine of development. One of the main reasons behind ...
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In spite of spending too much expenses for acquiring and importing technology in most of the developing countries. And even in most organizations. It can be observed that these technologies are not well absorbed and the technology does not act as the engine of development. One of the main reasons behind this is the inconsistency between the culture of society or organization and the intended technology. In order that technology plays its role appropriately and acts as the engine of development first on one hand the kind of technology should be analyzed and examined closely and then according to that technology the appropriate culture should be developed. On the other hand in acquiring and importing technology to the organization. First the culture of the organization should be analyzed and examined in order to make it congruent with the intended technology. In this article an attempt was made to examine this kind of relation in Iran Khodro industrial group (sales and after sales service organization). In this paper first a brief literature survey on application of operations research in health care systems is presented. Then two problems the optimal allocation of ambulances and the scheduling of nursing personnel are discussed in details. Finally these two models will be applied on two real cases in Iranian health care system.
K. Feizee; A. R. Moghadasi
Volume 2, Issue 5 , June 2004, , Pages 49-70
Abstract
This article sheds light on the main reasons of moving organizations toward business process reengineering and the basic characteristics of information technology based business process reengineering. Then the main information technology oriented effective factors in business process reengineering are ...
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This article sheds light on the main reasons of moving organizations toward business process reengineering and the basic characteristics of information technology based business process reengineering. Then the main information technology oriented effective factors in business process reengineering are described. Indeed specific relations between information technology and business process reengineering are described. Indeed specific relations between information technology and business process reengineering are reviewed. At the end of this article the main functions of information technology in this process are classified and defined.
Rohollah sohrabi; AbolfazI Kazazi; Jahanyar B. Soofi
Volume 6, Issue 17 , September 2007, , Pages 49-73
Abstract
Although the importance of Agility in supply chain in many different industries is clear, and being responsive, customer oriented and, flexible is obvious in management and organizations, Iran big oil companies do not pay enough attention to designing and implementation of their supply chains. The purpose ...
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Although the importance of Agility in supply chain in many different industries is clear, and being responsive, customer oriented and, flexible is obvious in management and organizations, Iran big oil companies do not pay enough attention to designing and implementation of their supply chains. The purpose of this article is conceptualizing and defining significant criteria and attributes for Supply Chain Agility Evaluation and measurement in National Iranian Oil Company the case of NISOC. For that acceptable literature review, qualitative research methods such as Delphi and case study research and quantitative methods such as statistical and structural equation modeling (SEM) have been used.
Abolfazl Kazzazi; Maghsood Amiri; Fatemeh Rahbar Yaghoobi
Volume 8, Issue 20 , March 2011, , Pages 49-79
Abstract
In This paper, application of MCDM techniques in evaluation and ranking of Temad Co. strategies has been considered. Statistical target group, as "expert group" has been chosen among company's managers to identify strategies and evaluate them. At the first phase, strategies have been deducted with SWOT ...
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In This paper, application of MCDM techniques in evaluation and ranking of Temad Co. strategies has been considered. Statistical target group, as "expert group" has been chosen among company's managers to identify strategies and evaluate them. At the first phase, strategies have been deducted with SWOT technique and at the second phase, they have been ranked by ELECTR III technique. Criteria for evaluating strategies gathered among different resources and got summarized according to strategic experts' ideas. Weight of criteria has determined by RTC or PCT technique and thresholds have been dedicated by decision makers. To reduce uncertainty of decision making, ranking has been done in fuzzy situation. Furthermore, for assessing efficiency of results, sensitivity analysis has been implemented with two approaches. According to final results, evaluation and ranking of strategies can be done well by means of ELECTRE III technique.
