Pub Date : 2021-12-30DOI: 10.1080/17477778.2021.2015259
Thomas Reiten Bovim, Anders N. Gullhav, H. Andersson, Jostien Dale, Kjetil Karlsen
ABSTRACT The work presented in this paper is based on two projects that were conducted at St. Olavs Hospital (Norway) when preparing for the COVID-19 pandemic. Three discrete event simulation models are provided to evaluate the resource requirements during the peak of the pandemic. First, we estimate the number of beds needed in the emergency department (ED). In the second model, we estimate the number of ambulances required to maintain prepandemic response times for emergency patients. The third model is a coupling of the two former models, and it is used to study the effects of ED boarding time for COVID-19 patients. The resource needs are analysed under different COVID-19 testing policies. A strict testing policy increases the bed requirements in the ED, while it has the opposite effect for ambulances. Two distinct mechanisms causing boarding time are found. The effects from boarding time are most prominent during night and weekends.
{"title":"Simulating emergency patient flow during the COVID-19 pandemic","authors":"Thomas Reiten Bovim, Anders N. Gullhav, H. Andersson, Jostien Dale, Kjetil Karlsen","doi":"10.1080/17477778.2021.2015259","DOIUrl":"https://doi.org/10.1080/17477778.2021.2015259","url":null,"abstract":"ABSTRACT The work presented in this paper is based on two projects that were conducted at St. Olavs Hospital (Norway) when preparing for the COVID-19 pandemic. Three discrete event simulation models are provided to evaluate the resource requirements during the peak of the pandemic. First, we estimate the number of beds needed in the emergency department (ED). In the second model, we estimate the number of ambulances required to maintain prepandemic response times for emergency patients. The third model is a coupling of the two former models, and it is used to study the effects of ED boarding time for COVID-19 patients. The resource needs are analysed under different COVID-19 testing policies. A strict testing policy increases the bed requirements in the ED, while it has the opposite effect for ambulances. Two distinct mechanisms causing boarding time are found. The effects from boarding time are most prominent during night and weekends.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"407 - 421"},"PeriodicalIF":2.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42622445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-29DOI: 10.1080/17477778.2021.2015260
Zeinab Rahimi Rise, M. Ershadi
ABSTRACT There are many problems with hospital departments that decrease patients’ satisfaction and hospitals’ performance. Although there are many qualitative and quantitative methods to improve related performances, some of them consider a single department and the rest don't consider related priorities. Therefore, this paper proposes an integrated model based on Six Sigma to consider the performances of all departments with priorities based on experts’ knowledge. This model utilizes qualitative methods including fishbone diagrams and Healthcare Failure Mode and Effect Analysis to find problems and their priorities based on experts’ knowledge and data. Then, quantitative methods including a mathematical model, Discrete Event Simulation, and Non-dominated Sorting Genetic Algorithm II are utilized to find solutions for preferred problems as a simulation-based multi-objective optimization model. Based on a case study in a well-known general hospital, the proposed model finds the hospital’s most important problems and represents the impacts of different improvement plans before implementation.
{"title":"An integrated HFMEA simulation-based multi-objective optimisation model to improve the performances of hospitals: A case study","authors":"Zeinab Rahimi Rise, M. Ershadi","doi":"10.1080/17477778.2021.2015260","DOIUrl":"https://doi.org/10.1080/17477778.2021.2015260","url":null,"abstract":"ABSTRACT There are many problems with hospital departments that decrease patients’ satisfaction and hospitals’ performance. Although there are many qualitative and quantitative methods to improve related performances, some of them consider a single department and the rest don't consider related priorities. Therefore, this paper proposes an integrated model based on Six Sigma to consider the performances of all departments with priorities based on experts’ knowledge. This model utilizes qualitative methods including fishbone diagrams and Healthcare Failure Mode and Effect Analysis to find problems and their priorities based on experts’ knowledge and data. Then, quantitative methods including a mathematical model, Discrete Event Simulation, and Non-dominated Sorting Genetic Algorithm II are utilized to find solutions for preferred problems as a simulation-based multi-objective optimization model. Based on a case study in a well-known general hospital, the proposed model finds the hospital’s most important problems and represents the impacts of different improvement plans before implementation.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"422 - 443"},"PeriodicalIF":2.5,"publicationDate":"2021-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41851599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-12DOI: 10.1080/17477778.2021.2007807
Zhiguo Wang, T. S. Ng, weir Ee
ABSTRACT Industrial symbiosis involves the coordination and cooperation of different production firms to exchange and reuse waste products as substitute input materials, reducing virgin material consumption and waste disposal. This work develops a system dynamics model to simulate the capacity investment and formation patterns of self-interested production agents involved in an industrial symbiosis network. The developed model can help decision-makers visualise the rate and dynamics of capacity formation and waste material exchanges in the system, test the effect of different capacity planning and incentivisation strategies, and investigate the impact of price disruptions. Numerical studies are performed based on a bread waste case study in Singapore. Various sensitivity analyses have been conducted and several important insights are obtained from the simulation results, including how a coordinated capacity formation model can be more effective than an uncoordinated one in the industrial symbiosis.
{"title":"A system dynamics model for industrial symbiosis capacity formation","authors":"Zhiguo Wang, T. S. Ng, weir Ee","doi":"10.1080/17477778.2021.2007807","DOIUrl":"https://doi.org/10.1080/17477778.2021.2007807","url":null,"abstract":"ABSTRACT Industrial symbiosis involves the coordination and cooperation of different production firms to exchange and reuse waste products as substitute input materials, reducing virgin material consumption and waste disposal. This work develops a system dynamics model to simulate the capacity investment and formation patterns of self-interested production agents involved in an industrial symbiosis network. The developed model can help decision-makers visualise the rate and dynamics of capacity formation and waste material exchanges in the system, test the effect of different capacity planning and incentivisation strategies, and investigate the impact of price disruptions. Numerical studies are performed based on a bread waste case study in Singapore. Various sensitivity analyses have been conducted and several important insights are obtained from the simulation results, including how a coordinated capacity formation model can be more effective than an uncoordinated one in the industrial symbiosis.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"381 - 406"},"PeriodicalIF":2.5,"publicationDate":"2021-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43388766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-06DOI: 10.1080/17477778.2021.2007808
Guangyu Zou, Ming Gao, Jiafu Tang, L. Yilmaz
ABSTRACT With the rapid development of Online to Offline (O2O) business, millions of transactions each day along with the varying processing time of merchants and the complexity of traffic conditions pose significant challenges to effective and efficient delivery of orders. This paper studies the complex adaptive dynamics of O2O platforms by combining the behaviors of customers, merchants, dispatcher, and couriers in the context of a multi-agent model. Serving as a testbed, the simulation model enables the evaluation of alternative order delivery strategies. Preliminary experimental results show that TSP-based delivery strategy is more efficient than the nearer merchant assignment strategy. As an important property, the larger load capacity of couriers is beneficial to improve the completion rate of orders rather than the completion time. Finally, the experiment using the real road network and the real order data demonstrates the applicability of the proposed multi-agent model of O2O platform in the real scenario.
{"title":"Simulation of online food ordering delivery strategies using multi-agent system models","authors":"Guangyu Zou, Ming Gao, Jiafu Tang, L. Yilmaz","doi":"10.1080/17477778.2021.2007808","DOIUrl":"https://doi.org/10.1080/17477778.2021.2007808","url":null,"abstract":"ABSTRACT With the rapid development of Online to Offline (O2O) business, millions of transactions each day along with the varying processing time of merchants and the complexity of traffic conditions pose significant challenges to effective and efficient delivery of orders. This paper studies the complex adaptive dynamics of O2O platforms by combining the behaviors of customers, merchants, dispatcher, and couriers in the context of a multi-agent model. Serving as a testbed, the simulation model enables the evaluation of alternative order delivery strategies. Preliminary experimental results show that TSP-based delivery strategy is more efficient than the nearer merchant assignment strategy. As an important property, the larger load capacity of couriers is beneficial to improve the completion rate of orders rather than the completion time. Finally, the experiment using the real road network and the real order data demonstrates the applicability of the proposed multi-agent model of O2O platform in the real scenario.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"297 - 311"},"PeriodicalIF":2.5,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44420235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-09DOI: 10.1080/17477778.2021.1992312
Geraint I. Palmer, Yawen Tian
ABSTRACT Implementation of hybrid simulation is not well documented, and often obscured behind commercial software packages. Here two implementation approaches for integrating discrete event simulation and systems dynamics are presented in an open, reproducible framework, built with the Ciw library in Python. These two implementation approaches, denoted here by and , correspond to two different process environments for DES+SD hybrid simulations. The models contribute to a collection of accessible and transparent hybrid simulations to be reproduced, scrutinised, built upon, and further developed. This paper also presents discussion on the lessons learned from these implementations, including the appropriateness of the models for different process environments, their ability to capture the full variability of a system, and subtleties in their synchronicity.
{"title":"Implementing hybrid simulations that integrate DES+SD in Python","authors":"Geraint I. Palmer, Yawen Tian","doi":"10.1080/17477778.2021.1992312","DOIUrl":"https://doi.org/10.1080/17477778.2021.1992312","url":null,"abstract":"ABSTRACT Implementation of hybrid simulation is not well documented, and often obscured behind commercial software packages. Here two implementation approaches for integrating discrete event simulation and systems dynamics are presented in an open, reproducible framework, built with the Ciw library in Python. These two implementation approaches, denoted here by and , correspond to two different process environments for DES+SD hybrid simulations. The models contribute to a collection of accessible and transparent hybrid simulations to be reproduced, scrutinised, built upon, and further developed. This paper also presents discussion on the lessons learned from these implementations, including the appropriateness of the models for different process environments, their ability to capture the full variability of a system, and subtleties in their synchronicity.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"240 - 256"},"PeriodicalIF":2.5,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46651232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-26DOI: 10.1080/17477778.2021.1991850
A. G. Qasem, Faisal Aqlan, Abdulrahman Shamsan, Mohammed Alhendi
ABSTRACT In order to minimise wastes and losses in perishable Food Supply Chains (FSCs), it is crucially important to control inventory and organise the flow of material and information throughout supply chains. In this study, Basestock-Constant Work-in-Process (B-CONWIP), a pull-based inventory control policy, is proposed to control inventory in perishable FSCs. The effectiveness of the B-CONWIP policy is investigated for a three-echelon perishable FSC using a simulation-optimisation approach. The B-CONWIP policy is compared with two existing basestock policies (BSPs): continuous review (s, S) policy and BSP-low-Estimated Waste (BSP-low-EW), a periodic inventory review policy that outperforms other policies presented in the literature for perishable inventory. The objective is to minimise the total cost (i.e., sum of holding, deterioration, ordering, and shortage costs) while satisfying a predetermined service level. The study shows that B-CONWIP yields the lowest total cost, BSP-low-EW performs the second best, while (s, S) policy is the worst. It is also noted that, in spite of higher ordering cost for B-CONWIP compared to (s, S) policy and BSP-low-EW, B-CONWIP achieves the lowest total cost at all demand rate and volume variations tested. In conclusion, B-CONWIP is more flexible and robust than (s, S) and BSP-low-EW policies because of its ability to handle demand variations without major changes in control parameter values and cost measures.
摘要为了最大限度地减少易腐食品供应链中的浪费和损失，控制库存并组织整个供应链中材料和信息的流动至关重要。在本研究中，提出了一种基于拉动的库存控制策略——Basestock Constant Work In Process（B-CONWIP）来控制易腐FSC中的库存。使用模拟优化方法研究了三级易腐FSC的B-CONWIP策略的有效性。将B-CONWIP政策与两种现有的基本库存政策（BSP）进行比较：持续审查政策和BSP低估计废物（BSP低EW），这是一种定期库存审查政策，在易腐库存方面优于文献中提出的其他政策。目标是在满足预定服务水平的同时，将总成本（即持有、变质、订购和短缺成本的总和）降至最低。研究表明，B-CONWIP产生的总成本最低，BSP低EW表现第二好，而（s，s）策略表现最差。还应注意的是，尽管与（s，s）策略相比，B-CONWIP的订购成本更高，且BSP EW较低，但B-CONWIP在所有需求率和测试的数量变化下都实现了最低的总成本。总之，B-CONWIP比（s，s）和BSP低EW策略更灵活、更稳健，因为它能够在控制参数值和成本度量没有重大变化的情况下处理需求变化。
{"title":"A simulation-optimisation approach for production control strategies in perishable food supply chains","authors":"A. G. Qasem, Faisal Aqlan, Abdulrahman Shamsan, Mohammed Alhendi","doi":"10.1080/17477778.2021.1991850","DOIUrl":"https://doi.org/10.1080/17477778.2021.1991850","url":null,"abstract":"ABSTRACT In order to minimise wastes and losses in perishable Food Supply Chains (FSCs), it is crucially important to control inventory and organise the flow of material and information throughout supply chains. In this study, Basestock-Constant Work-in-Process (B-CONWIP), a pull-based inventory control policy, is proposed to control inventory in perishable FSCs. The effectiveness of the B-CONWIP policy is investigated for a three-echelon perishable FSC using a simulation-optimisation approach. The B-CONWIP policy is compared with two existing basestock policies (BSPs): continuous review (s, S) policy and BSP-low-Estimated Waste (BSP-low-EW), a periodic inventory review policy that outperforms other policies presented in the literature for perishable inventory. The objective is to minimise the total cost (i.e., sum of holding, deterioration, ordering, and shortage costs) while satisfying a predetermined service level. The study shows that B-CONWIP yields the lowest total cost, BSP-low-EW performs the second best, while (s, S) policy is the worst. It is also noted that, in spite of higher ordering cost for B-CONWIP compared to (s, S) policy and BSP-low-EW, B-CONWIP achieves the lowest total cost at all demand rate and volume variations tested. In conclusion, B-CONWIP is more flexible and robust than (s, S) and BSP-low-EW policies because of its ability to handle demand variations without major changes in control parameter values and cost measures.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"211 - 227"},"PeriodicalIF":2.5,"publicationDate":"2021-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47676329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-19DOI: 10.1080/17477778.2021.1992313
Benfei Zhu, Qiang Zhou, Yu Tian
ABSTRACT Considering the diversification of dry bulk terminal types and the complexity of terminal loading and unloading operations, a modular modelling method based on discrete event system specification (DEVS) modelling theory is proposed in this paper. First, we introduced the DEVS into the dry bulk terminal and explained the ideas and main steps of the DEVS-based modular modelling method. Second, a module library and model framework library for dry bulk terminals were developed, and the DEVS expression of the modules and model framework was given. Studies have shown that the production performance of a coal export terminal is generally positively correlated with ship loading and ship arrival density. Terminal operators can improve their ability to respond to future scenarios in two ways: upgrading berth levels and improving ship berthing strategies. The case verifies that the model framework and module library are effective, and the modelling method based on DEVS is feasible.
{"title":"DEVS-based modular modelling method of dry bulk terminals","authors":"Benfei Zhu, Qiang Zhou, Yu Tian","doi":"10.1080/17477778.2021.1992313","DOIUrl":"https://doi.org/10.1080/17477778.2021.1992313","url":null,"abstract":"ABSTRACT Considering the diversification of dry bulk terminal types and the complexity of terminal loading and unloading operations, a modular modelling method based on discrete event system specification (DEVS) modelling theory is proposed in this paper. First, we introduced the DEVS into the dry bulk terminal and explained the ideas and main steps of the DEVS-based modular modelling method. Second, a module library and model framework library for dry bulk terminals were developed, and the DEVS expression of the modules and model framework was given. Studies have shown that the production performance of a coal export terminal is generally positively correlated with ship loading and ship arrival density. Terminal operators can improve their ability to respond to future scenarios in two ways: upgrading berth levels and improving ship berthing strategies. The case verifies that the model framework and module library are effective, and the modelling method based on DEVS is feasible.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"257 - 278"},"PeriodicalIF":2.5,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43603775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-13DOI: 10.1080/17477778.2021.1955629
Ignacio Erazo, D. Goldsman
ABSTRACT We study properties of confidence intervals (CIs) for the difference of two Bernoulli distributions’ success parameters. The CIs under investigation range from the classical fixed-sample-size CI to sequential versions, possibly incorporating batching. For each CI method, we examine the attained coverage, as well as the trade-offs between the number of observations and stages required to obtain a desired CI width. We consider cases in which the two populations are completely independent, and we provide analytical and simulation results to measure the performance of the different methods. For the multi-stage methods, we find that a simple observation allocation rule based on comparing the sample standard deviations of the two populations is more efficient than taking equal sample sizes from both. We also show that the use of a moderate level of batching saves stages at only modest costs in sample size and coverage.
{"title":"Efficient confidence intervals for the difference of two Bernoulli distributions’ success parameters","authors":"Ignacio Erazo, D. Goldsman","doi":"10.1080/17477778.2021.1955629","DOIUrl":"https://doi.org/10.1080/17477778.2021.1955629","url":null,"abstract":"ABSTRACT We study properties of confidence intervals (CIs) for the difference of two Bernoulli distributions’ success parameters. The CIs under investigation range from the classical fixed-sample-size CI to sequential versions, possibly incorporating batching. For each CI method, we examine the attained coverage, as well as the trade-offs between the number of observations and stages required to obtain a desired CI width. We consider cases in which the two populations are completely independent, and we provide analytical and simulation results to measure the performance of the different methods. For the multi-stage methods, we find that a simple observation allocation rule based on comparing the sample standard deviations of the two populations is more efficient than taking equal sample sizes from both. We also show that the use of a moderate level of batching saves stages at only modest costs in sample size and coverage.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"76 - 93"},"PeriodicalIF":2.5,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44868546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-10DOI: 10.1080/17477778.2021.1982653
A. Naugle, Stephen J Verzi, K. Lakkaraju, L. Swiler, C. Warrender, Michael Bernard, Vicente Romero
ABSTRACT Measures of simulation model complexity generally focus on outputs; we propose measuring the complexity of a model’s causal structure to gain insight into its fundamental character. This article introduces tools for measuring causal complexity. First, we introduce a method for developing a model’s causal structure diagram, which characterises the causal interactions present in the code. Causal structure diagrams facilitate comparison of simulation models, including those from different paradigms. Next, we develop metrics for evaluating a model’s causal complexity using its causal structure diagram. We discuss cyclomatic complexity as a measure of the intricacy of causal structure and introduce two new metrics that incorporate the concept of feedback, a fundamental component of causal structure. The first new metric introduced here is feedback density, a measure of the cycle-based interconnectedness of causal structure. The second metric combines cyclomatic complexity and feedback density into a comprehensive causal complexity measure. Finally, we demonstrate these complexity metrics on simulation models from multiple paradigms and discuss potential uses and interpretations. These tools enable direct comparison of models across paradigms and provide a mechanism for measuring and discussing complexity based on a model’s fundamental assumptions and design.
{"title":"Feedback density and causal complexity of simulation model structure","authors":"A. Naugle, Stephen J Verzi, K. Lakkaraju, L. Swiler, C. Warrender, Michael Bernard, Vicente Romero","doi":"10.1080/17477778.2021.1982653","DOIUrl":"https://doi.org/10.1080/17477778.2021.1982653","url":null,"abstract":"ABSTRACT Measures of simulation model complexity generally focus on outputs; we propose measuring the complexity of a model’s causal structure to gain insight into its fundamental character. This article introduces tools for measuring causal complexity. First, we introduce a method for developing a model’s causal structure diagram, which characterises the causal interactions present in the code. Causal structure diagrams facilitate comparison of simulation models, including those from different paradigms. Next, we develop metrics for evaluating a model’s causal complexity using its causal structure diagram. We discuss cyclomatic complexity as a measure of the intricacy of causal structure and introduce two new metrics that incorporate the concept of feedback, a fundamental component of causal structure. The first new metric introduced here is feedback density, a measure of the cycle-based interconnectedness of causal structure. The second metric combines cyclomatic complexity and feedback density into a comprehensive causal complexity measure. Finally, we demonstrate these complexity metrics on simulation models from multiple paradigms and discuss potential uses and interpretations. These tools enable direct comparison of models across paradigms and provide a mechanism for measuring and discussing complexity based on a model’s fundamental assumptions and design.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"229 - 239"},"PeriodicalIF":2.5,"publicationDate":"2021-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46778741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.1080/17477778.2021.1981784
Vasiliki Amarantou, D. Chatzoudes, Vassilios Angelidis, Alexandros Xanthopoulos, P. Chatzoglou
ABSTRACT This paper presents the results concerning the evaluation of the processes of an Emergency Department (ED). Based on the analysis of both processes and data flow, a simulation model of patient throughput in the ED has been developed. Simulation results, obtained using the JaamSim software, pointed out the strengths and weaknesses of the departments’ operations. Then, several alternative scenarios (hypothetical solutions) were created and tested, while the results were thoroughly analysed. In order to prioritise the several scenarios, two hierarchical processes were used. Firstly, a multicriteria table was developed based on decision makers’ personal preference. Total length of stay was acknowledged as the factor with the higher importance. Consequently, the application of an analytical hierarchical process (AHP) managed to verify the primary ranking. A comparison of the proposed ideas was attempted, featuring the implementation of a fast track unit as the best practice.
{"title":"Improving the operations of an emergency department (ED) using a combined approach of simulation and analytical hierarchical process (AHP)","authors":"Vasiliki Amarantou, D. Chatzoudes, Vassilios Angelidis, Alexandros Xanthopoulos, P. Chatzoglou","doi":"10.1080/17477778.2021.1981784","DOIUrl":"https://doi.org/10.1080/17477778.2021.1981784","url":null,"abstract":"ABSTRACT This paper presents the results concerning the evaluation of the processes of an Emergency Department (ED). Based on the analysis of both processes and data flow, a simulation model of patient throughput in the ED has been developed. Simulation results, obtained using the JaamSim software, pointed out the strengths and weaknesses of the departments’ operations. Then, several alternative scenarios (hypothetical solutions) were created and tested, while the results were thoroughly analysed. In order to prioritise the several scenarios, two hierarchical processes were used. Firstly, a multicriteria table was developed based on decision makers’ personal preference. Total length of stay was acknowledged as the factor with the higher importance. Consequently, the application of an analytical hierarchical process (AHP) managed to verify the primary ranking. A comparison of the proposed ideas was attempted, featuring the implementation of a fast track unit as the best practice.","PeriodicalId":51296,"journal":{"name":"Journal of Simulation","volume":"17 1","pages":"193 - 210"},"PeriodicalIF":2.5,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45611308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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