discrete event simulation

The lack of information systems, use of manual correspondence, as well as lack of proper transparency and traceability of information throughout the computer supply chain in Isfahan's education schools, have created challenges for the organization that have reduced efficiency and supply chain responsiveness. This study tries to investigate the effects of implementing blockchain technology on a supply chain through which computer parts are provided for Education & Development organizations in Isfahan, Iran.

In this study, through a discrete-event simulation of smart contracts based on the Ethereum network, the effects of this technology on the performance of the mentioned supply chain are investigated. First, by examining the current structure of the supply chain, members and processes, the relevant subsystems affecting supply chain performance are identified. The smart contracts corresponding to the selected subsystems are then developed using the Solidity programming language for the Ethereum blockchain network. Finally, using discrete event simulation, two different models of supply chain process are devised, one for representing current-method and the other which is based on blockchain technology for both of which, the performance results are extracted.

The comparison of the results shows that blockchain technology has the capacity to have a positive effect on the supply chain performance and while increasing transparency and improving traceability, it can also improve performance indicators in terms of time and cost.Practical implications: Implementing blockchain not only streamlines processes but also enables a more agile response to market demands, ultimately enhancing competitiveness. Furthermore, the findings underline the importance of investing in training and development for staff to navigate and utilize these new technologies effectively. Managers should also consider the significant role of real-time data visibility in enhancing collaboration and efficiency in their supply chains.

Due to the emerging nature of blockchain, especially its applications in the supply chain, most of the research done in this regard is theoretical and there are few practical implementations to investigate the effects of this technology on supply chain management and performance. In this study, using smart contracts within the Ethereum network, showcasing a practical simulation rather than a theoretical framework, the traditional structure of the supply chain is compared with the blockchain-enabled supply chain.

In order to achieve competitive advantages in uncertain situations, one of the big challenges that organizations are faced is the risk reduction through creating resilient supply chains. Supply Chain resilience refers to the ability of supply chain to respond to disruptions. Disruption is an unpredictable event that has different internal and external sources such as natural disasters and operational risks. In this paper, a simulation model has been presented for analyzing the disruption in the natural stone industry supply chain in one of the stone factories in Iran using Arena simulation software. The simulation model has been run 100 times and the simulation time has been assumed to be one year. The validation of the model has been done by comparing the simulation results with actual information by calculating the mean absolute error. Moreover, some scenarios have been made for disruption management and resilience creation in the system. Then, the performance of each scenario was evaluated based on some criteria include fill rate, backorder cost and total cost. Finally, the redundancy scenario was chosen to be run in the real world. The results showed that a backup production line would be set up in the factory to make the system more resilient.

War tourism in Iran, known as the Rahian-e Noor attracts several million visitors every year, during the year, especially on Nowruz holidays, from various memorials of the sacred defense operations on the western borders. The country visit. The purpose of this study is to evaluate the conditions of attendance in high -profile memorials on these trips. In this study, using the discrete simulation approach, Arvandkar's monument was selected as the study of the study. After examining the location geometry, different behavioral patterns of visitors have been extracted from this memoir and their distribution functions. This pattern has been analyzed in Erna software (Arena). On the basis of the output, the proposed scenario has been evaluated and its impact on the traffic of visiting the memory is evaluated. The purpose of this scenario was to reduce the number of pilgrims who, for whatever reason, could not use the memorial programs for any reason, and based on the simulation results of the scenario to stabilize the quality of visits from the peak visits, it was suggested that the capacity of the Landiraphic section, the number of narrators. Increase the routes and the number of narrators of the exhibition area.

According to the increasing role of competition among insurance companies in achieving greater market share, insurance companies are forced to seek methods for increasing customer satisfaction and loyalty. The insurance companies pay special attention to the provided service quality and thus the duration of service delivery plays an important role in customer perception of service quality.This study attempts to design a model for increasing customer satisfaction and its effect on the market of insurance sales by using simulation paradigms. The present study is descriptive in terms of purpose because it tests the relationship between the declared variables during the research in a particular community and in terms of method, a quantitative study based on the mathematical modeling approach with combined simulation paradigms using Anylogic software. The research findings show the designed model is matched with the real world, which means the output data is accurate and valid. After relating the Discrete Event Simulation Model by identifying the interaction points with the System Dynamics Simulation Model, the mixed scenario in increasing sales has been implemented. Considering the Discrete Event Simulation Model and System Dynamics Model are implemented interactively with each other at the beginning of the simulation model, so due to high rate of customer satisfaction, the input rate is raised by the System Dynamics Model and percentage of employee performance is increased. As the number of dissatisfied customers increases over a period of time, the input rate is reduced by the System Dynamics Model until the system is finally balanced.

Due to the competitiveness of production over the past years, managers have been trying to improve their business performance by increasing productivity and profitability. Maintenance plays an important role in increasing the efficiency and effectiveness of production lines, reducing costs and improving quality. In this paper, a model is presented for the simulation of JIT production systems in different operating conditions with various maintenance policies. The simulation model is designed for a production line that includes five work stations. The results show that the use of CBM can improve the productivity and profitability of production lines.

This study applies a discrete event simulation to improve the performance of hospital emergency department in order to reduce the waiting time for patients and optimize the resources. First, a simulation model is developed based on flow of patients in an emergency department using ARENA software; then, the simulation model is run 180 times for any feasible scenario including some physicians, emergency medicine specialists, nurses, acute phase cure unit, injection unit, supervised ward, and ICU unit. In the next step, two data envelopment analysis methods are used for ranking the scenarios. Ranking of DEA methods showed that the scenario number 39 is the best choice in both methods. Non-parametric Spearman-Row and Kendal-Tau tests were used to determine the correlation among the results of ranking methods. The results of the two tests (0.93 and 0.81, respectively) indicated a significant correlation among DEA ranking methods. The results of case study showed that the scenario 39 is the best scenario among all the 44 feasible scenarios defined in both DEA methods; that is, there should be 2 general physicians, 1 emergency medicine specialist, 16 nurses in the supervised ward, 5 nurses in the acute care unit, 2 beds in the injection room, 22 beds in the supervised ward and 16 beds in the acute care unit.

The increasing attention to customer demands in the product process, and the inevitable features and costs of production processes has led researchers to manage orders and choose the right policy for inventory management. This article identifies the structure for determining the optimal location of the Customer Order Decoupling Point and the optimal inventory management policy as one of the most important strategic decisions in the production process. So, we developed a discrete-event simulation model for realistic calculation of cost and Flow time, under different scenarios, and we used the production and sales information of a chemical plant for validation and implementation of the model. The results suggest that the use of a hybrid inventory management policy reduces the cost and delivery time.

Since the analysis of complex services systems by using mathematical modeling techniques, with considering the random patterns prevailing in them, is very difficult or impossible, improvement guidelines are often followed based on the professional's experience and descriptive analysis. In this paper, by employing the discrete event computer simulation approach, criminal trial system has been quantitatively analyzed in a selected court in Iran and appropriate operational strategies to improve two system performance indicators has been provided using statistical tools such as Design of Experiments, Hypothesis testing, Regression and Sensitivity analysis methods and multi-objective optimization. The simulation results show that by using the proposed scenarios, a reduction of 27% in average responding time on penal claims and simultaneously a reduction of 80% in repeated referral rate can be expected. In this study, in order to assess the effects of more changes by defining artificial response variables, validation of simulation models is also evaluated.

Due to the increasing health care organizations costs, their requirement to increase the quality, and also the complexity of their systems, the issue of the change and improvement to the systems has got really important. It was crucial to know which of methods and scenarios for the change of the systems, especially in the resources, lead to better conditions and this topic caused major issues. In this regard, discrete – event simulation as one of the decision making tools in operations research based on random data, has significantly helped policy makers and a managers. In this study, firstly, the key performance measures of Ghaem hospital emergency system using past publications and experts’ suggestions were identified. Then this system was modeled and simulated using Arena software. After weighting the criteria by AHP method, the scenarios of the experts were defined.  Finally they were ranked using PROMETHEE method and the most suitable scenario was determined.