International Journal of Simulation and Process Modelling (17 papers in press)
Service-oriented architecture-based design of bank-ATM and its verification with Petri net
by Amar Nath, Santanu Kumar Rath
Abstract: In the present era, IT-enabled business applications are very much observed to be pervasive and felt to be essential to manage an organisation. An organisation needs to update and upgrade its strategies to meet the challenges by adopting an IT-enabled solution to meet the agile customer requirements and market demand. An organisation has to embrace and underline technology that can be updated and modified without any severe bottlenecks. Service-Oriented Architecture (SOA) is one of the various architectural styles that provide agility to the organisation. SOA can help to meet different changes in requirements, viz., service composition, model-driven development, and service virtualisation. This paper illustrates the application of SOA in designing and implementing Automated Teller Machine (ATM) services, helpful in banking transactions. An ATM is a unit in the banking system, which is an embedded system that works on a distributed architecture. The incorporation of various services and their orchestration is implemented by using the Business Process Execution Language (BPEL) module under the OpenESB framework. However, in a complex and dynamic network environment, it is not easy to guarantee the quality of the BPEL process. So, it is very much essential to develop a proper BPEL process and validate it. In this study, the validation of the BPEL model is carried out by using the Petri net tool. The verification and validation activities are often considered essential to ensure the correctness of the system. The verification results obtained in this study are quite encouraging and prove validity.
Keywords: design of bank-ATM; improving bank-ATM performance; service-oriented architecture; orchestration of bank's services; verification with Petri net.
Simulation-based improvement and modification for performances of hospitals: a case study
by Mohammad Mahdi Ershadi, Ahmad Shafaeizadeh
Abstract: It is necessary to improve the process of service provided to patients owing to increased patient referrals and the variety of patients visiting hospitals. Besides, patients satisfaction is affected by admission methods of the hospital, availability of its resources, admission waiting time, resource wastes, and patient feedback analysis. Therefore, hospital managers need to find current prioritised problems of the hospital and make efforts to solve various therapeutic processes about defined problems using appropriate planning. The prioritised problems are changed after every improvement scenario implementation. Besides, some results are unpredictable owing to the complexity of the hospital. Therefore, a simulation model for all departments of the hospital is proposed with a mathematical model and Taguchi method based on the real data obtained from a hospital. Decreasing resource wastes, the number of patients in the queue, and waiting time in different departments and increasing value-added time, use of resources, and productivity are considered in a mathematical model. All improvement scenarios are evaluated using the proposed model before implementation. Besides, FMEA is used to find the priority of problems and guide improvement teams. By analyzing these scenarios and examining their appropriate combination, a suitable plan designed for prioritised problems. The best improvement scenarios and their effects are defined using the proposed model in this paper. After the actual implementation of them, the difference between reality and the expected condition was less than 10%.
Keywords: discrete event simulation; multi-objective model; hospitals; healthcare system; failure modes and effects analysis.
Multilevel model of spatially allocated time use for takeout food ordering behaviour: a case study
by Jingyao Li, Shengchuan Zhao, Junyi Zhang
Abstract: The development of food delivery services in China has affected peoples space choice of dining. However, few studies have explored the influence of food delivery services in both space and time dimensions. To explore the activity decision-making mechanism which contains space and time dimensions, weekly panel data of spatially allocated time use was collected from undergraduate students. A multilevel spatially allocated time use model was built and based on the principle of utility maximisation. The research results prove that the spatially allocated time use in a whole day is a comprehensive decision-making process under the constraints of cross-sections of multiday survey, life circles and individual attributes. Takeout food ordering behaviour decreases travel demand for dining and other non-essential activities. It is concluded that takeout food ordering behaviour affects individual decision-making of spatially allocated time use in the whole day for both activity content and activity space.
Keywords: multilevel spatially allocated time use model; takeout food ordering behaviour; life circle; panel data of time use; undergraduate students.
Simulation-based decision support for production improvement using ntegrated ergonomic and productivity performance indicators
by Regina Dias Barkokebas, Chelsea Ritter, Mohamed Al-Hussein, Xinming Li
Abstract: Workers in the construction manufacturing industry are exposed to labour-intensive tasks with ergonomic risks, such as forceful exertion and repetitive motion. Owing to increased productivity and repetitive motions resulting from improvement initiatives implemented in offsite construction manufacturing, the investigation of ergonomic risks associated with these changes is needed. In this context, this paper explores an existing panelised floor production line aiming to minimise its ergonomic risks while improving its current productivity rate. Information pertaining to human body motion and productivity is extracted from video recordings. The ergonomic risks associated with specific tasks are identified using two existing ergonomic risk assessment methods: the rapid entire body assessment and the rapid upper limb assessment. A simulation model is used to evaluate various process improvements from the perspective of both ergonomic risks and productivity to support the decision-making process and the prioritisation of process changes in the factory.
Keywords: simulation; process modelling; decision support systems; integrated decision-making processes; production improvements; ergonomics; ergonomic risk assessments; Rapid Entire Body Assessment; REBA; Rapid Upper Limb Assessment; RULA; productivity performance indicators; productivity; offsite construction.
A novel energy conservation method for office building lighting system
by Xinyin Xu, Zhengtian Wu, Baochuan Fu
Abstract: There is a trade-off between human visual performance and energy cost. With an open office as the research object, personalised control with demand and daylight adaptation is considered in a lighting system with multiple illumination devices. Each luminaire and workspace is equipped with illumination sensors and intelligent units. The intelligent dimming model of the lighting system is established, and the optimal dimming value of the luminaire is determined by the constraint control algorithm. The summation of the power consumed by all LED lights and the other devices is used as the objective function. A simulation study was conducted in this research work with DIALux to verify the lighting system and control method. The simulation results show that the proposed control strategy can automatically adjust illumination in real time according to the change of daylight and personal demand.
Keywords: energy conservation; lighting system; constraint control; daylight; simulation.
Evaluating the impact of shared situational awareness on combat effectiveness in symmetric engagements
by Mahmoud Khasawneh, Nevan Shearer, Ghaith Rabadi, Shannon Bowling, Raed Jaradat
Abstract: The information age combat model (IACM) is a popular representation of Network Centric Operations (NCO). NCO is a military doctrine championed by the USA. This paper presents the results of a discrete event simulation (DES) of the IACM. The objective is to understand the impact of shared situational awareness on combat effectiveness in symmetric engagements. Symmetric in this context means that the battle engagements studied involved units having an equal number of sensors, deciders, and influencers. After model verification, the results of the linear and nonlinear regression analyses will be presented and discussed. The analyses have been carried out on the aggregated data first and then the data was disaggregated to focus on high percentage win engagements and evenly-matched engagements. The focus will be on highlighting the utility of the performance metrics defined and used in previous IACM research studies.
Keywords: network centric operations; information age combat model; shared situational awareness; discrete event simulation; performance metrics.
Using scenario-based simulation modelling to optimise aircraft inspection scheduling
by Rubayat Islam, Shengyong Wang, Chen Ling
Abstract: The main aim of this paper is to generate different visual simulation modelling scenarios for performing inspection operations on different Federal Aviation Administration (FAA) facilities. Different combinations of aircraft and routes are scheduled to design different scenarios for performing inspections. For assigning aircraft into the model, a study of FAA current fleet composition is made. To make the model robust, probabilistic distribution is introduced into the modelling approach. For every modelling approach or scenario, a various number of experiments with thousands of replications are scheduled to generate a maximum, minimum and average number of inspections over a year that can be performed through that modelling approach. Furthermore, a comparison of the different modelling approaches is made based on the number of inspections made by each model over a year.
Keywords: route planning; flight control; probabilistic approach; system design; transportation planning; robust model.
A conceptual process model to improve voter participation in Nigerian elections
by Ashiru Simon, Gabriel Lazarus Dams, Salome Danjuma Mammanjabs
Abstract: Insecurity at every polling unit is one of the major reasons why the number of voters participating in Nigerian elections is continuously on the decrease. In the 2011 presidential election for instance, the number of people killed was estimated to be between 800 and 1000. More so, statistics has it that voter turnout for the presidential elections in 2007, 2011 and 2015 was 58%, 53.68% and 43.65%, respectively, showing a progressive decrease. In this paper, a process model for the election system currently used in Nigeria is designed to capture the voting system. The designed process model is modified by embedding an existing technology known as Unstructured Supplementary Service Data (USSD). A prototype is developed for demonstration. The adoption and deployment of the prototype will encourage the turnout of eligible voters and minimise the degree of rigging, human labour, loss of lives and improvement of overall voting time.
Keywords: Nigeria elections; USSD; conceptual process model; prototype; election process; voter participation.
Realistic scenario modelling for a building power supply and distribution system based on non-intrusive load monitoring
by Jundong Fu, Ying Zhao
Abstract: In power supply and distribution systems in buildings, the conventional designs of loads are fictitious, and it is difficult to find the vulnerabilities timely. In order to solve this problem, a realistic scenario modelling method is proposed. Aiming at the input of the power consumption data in a realistic scenario model, a non-intrusive load monitoring method is used, combined with sliding window switching event detection method of electrical appliance, and a sequence to short-sequence deep learning model is also established whose input vectors are composed of switching time and total power data. The input vectors in the deep learning model can be decomposed to the individual electrical appliances. Compared with CO and FHMM algorithm, the decomposition results of this model are excellent in precision, recall, F1 score and accuracy. Also, it is more practical and accurate to replace the estimated data with the electricity consumption data obtained by NILM in the realistic scenario modelling.
Keywords: realistic scenario modeling; non-intrusive load monitoring; deep learning; sliding window; sequence to short-sequence; attention mechanism.
Assessing escalator [pedestrian traffic dynamics amid COVID-19 pandemic using hybrid simulation
by Konstantinos Mykoniatis, Anastasia Angelopoulou, Tianqi Gao Smith
Abstract: Pedestrian behaviour in urban spaces has abruptly changed amidst the COVID-19 pandemic owing to government-issued restrictions such as social distancing. It is unclear whether pedestrian behaviour will remain altered and/or urban spaces will be changed accordingly post-pandemic. Taking these changes and uncertainties, as well as the unique characteristics of pedestrian traffic as opposed to vehicle traffic, into consideration, this study creates a hybrid simulation model using the AnyLogic simulation software. The simulation model can be used to examine the efficiency of several types of escalator pedestrian behaviour in non-crowded scenarios, such as emergency/evacuation vs. regular operation, capacity and number of available escalators, escalator dimensions (e.g., height and length) and speed, and pedestrian preference (e.g., standing vs. walking). This generic simulation model allows future users to evaluate the efficiency of the escalator operation scenarios they would like to simulate by providing output measures such as time spent in system and throughput and allowing customisations of escalator dimensions and pedestrian-related parameters based on user-specific requirements.
Keywords: hybrid simulation; escalator; pedestrian; COVID-19 pandemic; social distancing.
Special Issue on: I3M 2018 Modelling and Simulation for Sustainable Development in Energy, Industry and Logistics
Dynamic bond graph modelling of a two-phase cooling system with experimental analysis
by Mohamed Kebdani, Geneviève Dauphin-Tanguy
Abstract: The power electronics components are a significant source of heat power, which must be managed in spite of the limitations of conventional cooling systems. In order to surpass these restrictions, an innovative heat transfer system is here investigated: Two-phase Loop Mechanically Pumped (TLMP). An instrumented test rig is built with temperatures, pressures and mass flow rate sensors to analyse the flow response in both steady and transient states. In this work, we focus on the pump-pipes subsystem. The results confirm the systems ability to manage heat power dissipation by maintaining a stable power electronics temperature. In addition, the experiment results validate a thermo-hydraulic model based on bond graph theory. The variables used to simulate phase-change phenomena are: mass enthalpy, temperature and pressure. This modelling allows estimating the influence of external conditions on loop operation. Moreover, it offers sizing prospects for this kind of loop development on-board future missiles.
Keywords: cooling systems; thermal control; bond graphs; dynamic systems modelling; phase change; heat transfers; convection; conduction; turbomachines.
Special Issue on: I3M 2019 Simulation and Process Modelling of Tomorrow How 4.0 is Affecting R&D in Multiple Domains
Mesoscopic simulation model of the logistics system of concentrated sets of urban delivery locations
by David Lajos Sardi, Krisztian Bona
Abstract: In city logistics, the examination of the urban concentrated sets of delivery locations is an important new area. In these sets, there are a relatively large number of stores with significant goods traffic, which generates significant customer traffic, while their logistics systems are not properly designed. Despite all this, city logistics research projects do not specifically target this field. Earlier, only a few subsystems have been examined, so we started to study and model the concentrated sets of delivery locations generally. In our research, a mesoscopic level mathematical and a simulation model was developed in MS Excel, which can clearly show the performances and the costs in the current city logistics system, and the possible savings in the case of new, consolidation-based city logistics systems of the concentrated sets of delivery locations. Based on the results of the simulation runs performed by this model, it is clear that the performances and the emissions can be significantly reduced in the new systems, and the logistics costs of the new system will be less too. Additionally, this simulation model can be applied for the sizing of the city logistics junctions of the new systems and for ranking of these sets.
Keywords: logistics; city logistics; urban logistics; consolidation; modelling; simulation; Excel; mathematical model; topological model.
Integrating physical and virtual game-based simulation for operators training to enhance learning effectiveness: an application in hazardous industrial spaces
by Francesco Longo, Antonio Padovano, Lucia Gazzaneo, Giovanni Mirabelli, Alessandra Ferraro, Marco Pirozzi, Luciano Di Donato
Abstract: Inadequate training and lack of risk awareness are among the main causes of work-related accidents in industrial facilities and during hazardous tasks. Although new learning methods and technological tools, such as Virtual Reality (VR), have been largely deployed, they still do not find implementation on a large scale owing to different shortcomings. As opposed to traditional role-playing games based on long storyboards the trainee needs to complete, this research proposes the concept of 'virtual training pills' (VTPs), i.e. delivering learning content in the form of short educational games by using a common technological platform based on virtual, interactive and immersive reality. An application study has been conducted in the case of 'dead chambers' of a decommissioned nuclear power plant, which are classified as confined and pollution-suspected spaces. These areas represent a crucial and challenging environment for maintenance, regulation, installation of mechanical parts, cleaning, and other activities that in other industrial scenarios would have been normally conducted. The results of a randomised controlled experiment conducted with 14 subjects who were administered a Game Experience Questionnaire (GEQ) at the end of their training session proved the potential of this novel game-based learning approach. Short 'learning pills' have much higher effectiveness and are much more valuable than traditional role-playing games with long storyboards. This work also discusses the benefits of workforce training based on VTPs integrated with live exercises.
Keywords: confined space; game-based learning; virtual reality; simulation; process modelling.
Building a digital twin for IoT smart stores: a case in the retail and apparel industry
by Yasmina Maizi, Ygal Bendavid
Abstract: A Digital Twin (DT) is a digital representation of a physical object, process or system across its lifecycle, creating two similar systems (twins) connected by a permanent real-time data exchange to enable understanding, learning and decision taking. Today DTs are among the highest technological trends and have moved from concept to reality. Although the first implementations were conducted in the manufacturing sector as an enabler of Industry 4.0, their evolution is expected to transform the face of several industries. Even though there has been a considerable growth of interest among the scientific community in the DT concept, its application remains at a cradle stage and research in other sectors such as retail is very limited. Additionally, since an increasing number of companies are implementing Internet of Things (IoT) technologies, they may deploy a DT in the next years, and knowing the realistic impacts of DT on operations management is therefore of great interest. In this research paper, we aim to develop a DT prototype for service-oriented organisations in the retail sector. More specifically, we study the case of implementing a DT in smart stores and assess its impact on daily operations management performance using simulation.
Keywords: digital twin; simulation; retail; RFID technology; IoT.
Simulation-based optimisation for worker cross-training
by Johannes Karder, Andreas Beham, Viktoria A. Hauder, Klaus Altendorfer, Michael Affenzeller
Abstract: Worker cross-training is a problem arising in many companies that involve human work. To perform certain activities, workers are required to possess certain skills. Cross-trained workers possess multiple skills, which enables a more flexible deployment, but also incurs higher costs. Thus, companies seek to balance the available skills such that customer deadlines can be met in a cost-efficient way. In this work, we compare solution approaches for a simulation-based problem formulation with three objectives. We apply evolutionary multi-objective optimisation to a production system scenario with two lines and six workstations. Their performance is compared for a hard scenario where cross-training is essential to achieve high service levels. Results indicate that the algorithms are able to solve this three-objective formulation quite well using the described encoding and operators. Employing this technology at companies could lead to better qualification strategies and a better contribution of qualification efforts to company goals.
Keywords: worker cross-training; workforce qualification; encoding; multi-objective optimisation; NSGA-II; MOEA/D.
Special Issue on: ISM 2019 New Challenges and Solutions for Industry 4.0 and Smart Manufacturing
Blockchain-based solutions for agri-food supply chains: a survey
by Giovanni Mirabelli, Vittorio Solina
Abstract: In recent years, interest in blockchain technology has grown considerably, owing to its multiple properties, such as transparency, immutability, traceability, and security. Considering the significant number of recently published contributions about the use of blockchain-based solutions in the agri-food sector, in this paper we aim to collect and catalogue them. The main purpose is the identification of research trends and possible barriers to the large-scale spreading of this disruptive technology. Through a well-structured four-step research methodology, we systematically review 48 papers. The main result is that blockchain can be used not only to ensure complete food traceability, but also to protect workers' rights, limit the power of supply chain intermediaries, protect market prices, and enable reward mechanisms for the development of sustainable initiatives. However, there are still some open issues that limit its large-scale diffusion: lack of shared standards, limited number of real case studies, resistance by stakeholders, and restricted scalability.
Keywords: blockchain; agri-food supply chain; food traceability; internet of things; smart contract.
Construction logistics: a simulation case study to improve performance process
by Kamal Jaafar
Abstract: Logistics in construction in general is an old topic, which has been researched and studies by many scientists, engineers, and researchers. However, little attention was given to logistics management in the precast industry and was relatively ignored, especially in the United Arab Emirates (UAE), compared with the conventional construction industry (cast in-situ). This paper will talk in details about the forgotten part in construction logistics, which is the precast construction logistics management: specifically, the management of the precast stockyard layout in the precast concrete products industry. Designing an effective precast stockyard with effective storage and structural precast element retrieval is a very complex process. The complexity is because of the massive heavy precast elements products, unique lifting and tilting requirements, and the large number of panels produced and stocked. Thus, the paper will discuss how to ensure efficient storage and dispatch of precast elements, ease of rotation of precast elements within the precast stockyard, and a smooth precast element retrieval process from any stockyard. In addition, the paper will show how an effective stockyard layout can reduce the dispatch time, loading time, and queuing time of the precast elements within the stockyard. Finally, the paper will include simulation modelling using ARENA software to optimise, design, and test the new stockyard layout that we established and compare it with the current status of the precast stockyard. A 'what if' analysis will be implemented from the simulation model in order to cover various stockyard conditions, such as increased product production in the future.
Keywords: logistics; process optimisation; ARENA; stockyard management; construction.