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Systems, Volume 9, Issue 1 (March 2021) – 20 articles

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11 pages, 609 KiB  
Viewpoint
Ladders of Authority, Status, Responsibility and Ideology: Toward a Typology of Hierarchy in Social Systems
by A. Georges L. Romme
Systems 2021, 9(1), 20; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010020 - 15 Mar 2021
Cited by 4 | Viewed by 4632
Abstract
Hierarchy is a key characteristic of any complex system. This paper explores which notions of hierarchy are being used in the field of organization and management studies. Four distinct types of hierarchy are identified: a ladder of formal decision-making authority, a ladder of [...] Read more.
Hierarchy is a key characteristic of any complex system. This paper explores which notions of hierarchy are being used in the field of organization and management studies. Four distinct types of hierarchy are identified: a ladder of formal decision-making authority, a ladder of achieved status, a self-organized ladder of responsibility and an ideology-based ladder. A social mechanism-based perspective serves to define and distinguish these four types. Subsequently, the typology is further developed by comparing the four hierarchy types in terms of their tacit/explicitness, (in)transitivity and behavior- versus cognition-centeredness. This article contributes to the literature by dissecting the general metaphor of hierarchy into four different constructs and their social mechanisms, which serves to create a typology of the various ways in which complex social systems can be characterized as hierarchical. This typology can inform future research drawing on any type of hierarchy. Full article
(This article belongs to the Section Complex Systems)
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17 pages, 2504 KiB  
Article
The Architecture Design of Electrical Vehicle Infrastructure Using Viable System Model Approach
by Mahdi Boucetta, Niamat Ullah Ibne Hossain, Raed Jaradat, Charles Keating, Siham Tazzit and Morteza Nagahi
Systems 2021, 9(1), 19; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010019 - 09 Mar 2021
Cited by 5 | Viewed by 3551
Abstract
Exponential technological-based growth in industrialization and urbanization, and the ease of mobility that modern motorization offers have significantly transformed social structures and living standards. As a result, electric vehicles (EVs) have gained widespread popularity as a mode of sustainable transport. The increasing demand [...] Read more.
Exponential technological-based growth in industrialization and urbanization, and the ease of mobility that modern motorization offers have significantly transformed social structures and living standards. As a result, electric vehicles (EVs) have gained widespread popularity as a mode of sustainable transport. The increasing demand for of electric vehicles (EVs) has reduced the some of the environmental issues and urban space requirements for parking and road usage. The current body of EV literature is replete with different optimization and empirical approaches pertaining to the design and analysis of the EV ecosystem; however, probing the EV ecosystem from a management perspective has not been analyzed. To address this gap, this paper develops a systems-based framework to offer rigorous design and analysis of the EV ecosystem, with a focus on charging station location problems. The study framework includes: (1) examination of the EV charging station location problem through the lens of a systems perspective; (2) a systems view of EV ecosystem structure; and (3) development of a reference model for EV charging stations by adopting the viable system model. The paper concludes with the methodological implications and utility of the reference model to offer managerial insights for practitioners and stakeholders. Full article
(This article belongs to the Section Cybernetics)
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37 pages, 12992 KiB  
Article
VERDICT: A Language and Framework for Engineering Cyber Resilient and Safe System
by Baoluo Meng, Daniel Larraz, Kit Siu, Abha Moitra, John Interrante, William Smith, Saswata Paul, Daniel Prince, Heber Herencia-Zapana, M. Fareed Arif, Moosa Yahyazadeh, Vidhya Tekken Valapil, Michael Durling, Cesare Tinelli and Omar Chowdhury
Systems 2021, 9(1), 18; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010018 - 03 Mar 2021
Cited by 10 | Viewed by 4438
Abstract
The ever-increasing complexity of cyber-physical systems is driving the need for assurance of critical infrastructure and embedded systems. However, traditional methods to secure cyber-physical systems—e.g., using cyber best practices, adapting mechanisms from information technology systems, and penetration testing followed by patching—are becoming ineffective. [...] Read more.
The ever-increasing complexity of cyber-physical systems is driving the need for assurance of critical infrastructure and embedded systems. However, traditional methods to secure cyber-physical systems—e.g., using cyber best practices, adapting mechanisms from information technology systems, and penetration testing followed by patching—are becoming ineffective. This paper describes, in detail, Verification Evidence and Resilient Design In anticipation of Cybersecurity Threats (VERDICT), a language and framework to address cyber resiliency. When we use the term resiliency, we mean hardening a system such that it anticipates and withstands attacks. VERDICT analyzes a system in the face of cyber threats and recommends design improvements that can be applied early in the system engineering process. This is done in two steps: (1) Analyzing at the system architectural level, with respect to cyber and safety requirements and (2) by analyzing at the component behavioral level, with respect to a set of cyber-resiliency properties. The framework consists of three parts: (1) Model-Based Architectural Analysis and Synthesis (MBAAS); (2) Assurance Case Fragments Generation (ACFG); and (3) Cyber Resiliency Verifier (CRV). The VERDICT language is an Architecture Analysis and Design Language (AADL) annex for modeling the safety and security aspects of a system’s architecture. MBAAS performs probabilistic analyses, suggests defenses to mitigate attacks, and generates attack-defense trees and fault trees as evidence of resiliency and safety. It can also synthesize optimal defense solutions—with respect to implementation costs. In addition, ACFG assembles MBAAS evidence into goal structuring notation for certification purposes. CRV analyzes behavioral aspects of the system (i.e., the design model)—modeled using the Assume-Guarantee Reasoning Environment (AGREE) annex and checked against cyber resiliency properties using the Kind 2 model checker. When a property is proved or disproved, a minimal set of vital system components responsible for the proof/disproof are identified. CRV also provides rich and localized diagnostics so the user can quickly identify problems and fix the design model. This paper describes the VERDICT language and each part of the framework in detail and includes a case study to demonstrate the effectiveness of VERDICT—in this case, a delivery drone. Full article
(This article belongs to the Special Issue Engineering Resilient Systems)
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19 pages, 2705 KiB  
Article
A Systems Approach to Examining PhD Students’ Well-Being: An Australian Case
by Nina Dhirasasna, Emiliya Suprun, Stefen MacAskill, Mehdi Hafezi and Oz Sahin
Systems 2021, 9(1), 17; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010017 - 23 Feb 2021
Cited by 8 | Viewed by 4528
Abstract
Previous research regarding PhD students’ well-being (PhD-WB) has lacked a comprehensive and systemic analysis. This research engages with a systems approach to examine the multiple variables, including feedback mechanisms, which influence PhD-WB over time. The model was developed using a structural analysis method [...] Read more.
Previous research regarding PhD students’ well-being (PhD-WB) has lacked a comprehensive and systemic analysis. This research engages with a systems approach to examine the multiple variables, including feedback mechanisms, which influence PhD-WB over time. The model was developed using a structural analysis method (Cross-impact analysis MICMAC) that informed a causal loop diagram (CLD). The aim was to understand what promotes (drivers) and inhibits (barriers) PhD students’ well-being. The results show that PhD students’ well-being reflects an interplay between university, financial support, students’ mental and physical health, and family/friends. However, the analysis shows that the role of the drivers is dynamic, and they can become barriers in certain circumstances. This insight validates the application of systems thinking to illustrate the complexity of PhD students’ well-being. Full article
(This article belongs to the Section Systems Practice in Social Science)
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24 pages, 1842 KiB  
Article
Macro Patterns and Trends of U.S. Consumer Technological Innovation Diffusion Rates
by Albert Joseph Parvin, Jr. and Mario G. Beruvides
Systems 2021, 9(1), 16; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010016 - 18 Feb 2021
Cited by 5 | Viewed by 3440
Abstract
Macro-level trends and patterns are commonly used in business, science, finance, and engineering to provide insights and estimates to assist decision-makers. In this research effort, macro-level trends and patterns were explored on the diffusion rates of technological innovations, a component of a sorely [...] Read more.
Macro-level trends and patterns are commonly used in business, science, finance, and engineering to provide insights and estimates to assist decision-makers. In this research effort, macro-level trends and patterns were explored on the diffusion rates of technological innovations, a component of a sorely under-studied question in technology assessment: When should a technological innovation be abandoned? A quantitative exploratory data analysis (EDA)-based approach was employed to examine diffusion market data of 42 U.S. consumer technological innovations from the early 1900s to the 2010s to extract general macro-level knowledge on technological innovation diffusion rates. A goal of this effort is to grow diffusion rate knowledge to enable the development of general macro-based forecasting tools. Such tools would aid decision-makers in making informed and proactive decisions on when to abandon a technological innovation. This research offers several significant contributions to the macro-level understanding of the boundaries and likelihood of achieving a range of technological innovation diffusion rates. These contributions include the determination that the frequency of diffusion rates are positively skewed when ordered from slowest to fastest, and the identification and ranking of probability density functions that best represent the rates of technological innovation diffusion. Full article
(This article belongs to the Section Systems Engineering)
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24 pages, 1300 KiB  
Article
A Systemic Framework to Evaluate Student Satisfaction in Latin American Universities under the COVID-19 Pandemic
by Silvia Quispe-Prieto, Melissa Franchini Cavalcanti-Bandos, Manuel Caipa-Ramos, Alberto Paucar-Caceres and Héctor Heraldo Rojas-Jiménez
Systems 2021, 9(1), 15; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010015 - 12 Feb 2021
Cited by 20 | Viewed by 6365
Abstract
Latin American universities (LAUs) have been going through a serious lack of economic resources which has plunged them into a deep financial crisis. The COVID-19 pandemic has exacerbated this calamity. However, LAUs have implemented online teaching processes in order to mitigate the effects [...] Read more.
Latin American universities (LAUs) have been going through a serious lack of economic resources which has plunged them into a deep financial crisis. The COVID-19 pandemic has exacerbated this calamity. However, LAUs have implemented online teaching processes in order to mitigate the effects of scheduling and other classroom disruption. There is evidence that these modes of teaching have had a reasonable reception but the level of student satisfaction is yet unknown. This article takes a systemic view of the predicament facing LAUs. It represents the elements related to the disruption caused by COVID-19 in a rich picture, building a systemic framework to explore student satisfaction with remote teaching. Using a sample of 298 students from Brazil, Colombia, and Peru, the study analyzes their situation through: (a) Well-being, educational resources, and learning experience and; (b) General satisfaction with virtual classes. Applying exploratory factor analysis, this study identifies three dimensions: (a) satisfaction with support and adaptation in the virtual modality; (b) satisfaction with the interaction in the virtual classroom; and (c) satisfaction with the development of the study program. Medium/high scores for the dimensions indicate moderate/high levels of satisfaction. The findings suggest that there are still unsatisfied needs regarding access to digital resources and socio-emotional needs. This article could be of interest to Higher Education Institutions (HEI) planners dedicated to post-pandemic, virtual education. Full article
(This article belongs to the Special Issue Systemic Thinking in Times of the COVID-19 Pandemic Crisis)
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11 pages, 2690 KiB  
Article
Cancer as a System Dysfunction
by Khalid Saeed, Elizabeth F. Ryder and Amity L. Manning
Systems 2021, 9(1), 14; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010014 - 09 Feb 2021
Cited by 3 | Viewed by 2825
Abstract
In this paper, we describe a system dynamics model that views cancer as a dysfunction of the cellular system rather than as an ailment of cells. Our experiments with the model replicate the propagation of the ailment and the impacts of the treatments. [...] Read more.
In this paper, we describe a system dynamics model that views cancer as a dysfunction of the cellular system rather than as an ailment of cells. Our experiments with the model replicate the propagation of the ailment and the impacts of the treatments. It presents a concept that deviates from the pervasive view of cancer as a cell malfunction that has led to treatments aiming to destroy the rogue cells. It points to more holistic treatment options aiming at reforming cell interaction so the system can contain the growth of cancer cells. Further research is needed to explore the details for such options. Full article
(This article belongs to the Special Issue System Dynamics: Insights and Policy Innovation)
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14 pages, 1002 KiB  
Article
A Critical Inquiry into the Value of Systems Thinking in the Time of COVID-19 Crisis
by David Haley, Alberto Paucar-Caceres and Sandro Schlindwein
Systems 2021, 9(1), 13; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010013 - 03 Feb 2021
Cited by 20 | Viewed by 6675
Abstract
The COVID-19 pandemic offers an historic precedent to review and challenge the values of social, economic, environmental, and cultural belief systems. The concept of the “New Normal” and the experience of the global pandemic provide points of transition in thinking about our relationship [...] Read more.
The COVID-19 pandemic offers an historic precedent to review and challenge the values of social, economic, environmental, and cultural belief systems. The concept of the “New Normal” and the experience of the global pandemic provide points of transition in thinking about our relationship to our planet and to each other. These include the fragility of contemporary economics, dependency on industrialized urban infrastructures, and reliance on top-down governance, vulnerability to climate disasters, dislocation from the natural world, societal inequalities, and the loss of cultural memory. The paper considers the potential role of systems thinking in attempting to manage societies’ responses to the pandemic. To provide the methodological context in which some systems thinking can be applied to alleviate the pandemic, we conduct a focused literature review of systemic frameworks, and using examples from Brazil and England, the paper questions the validity of existing disaster management systems and proposes an integrated critical systems approach. Reflecting on these experiences, questions of systems criticality are further developed and considered in relation to critical recovery from disasters and as integral critical systems (ICS) to interrogate the intention of systems. Finally, the paper reflects upon the value of systems and the values embedded in systems that may or may not promote equitable well-being in recovery from disasters such as COVID-19. Full article
(This article belongs to the Special Issue Systemic Thinking in Times of the COVID-19 Pandemic Crisis)
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16 pages, 2802 KiB  
Article
Modeling for Rapid Systems Prototyping: Hospital Situational Awareness System Design
by Avi Shaked
Systems 2021, 9(1), 12; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010012 - 01 Feb 2021
Cited by 5 | Viewed by 3233
Abstract
The COVID-19 pandemic caught hospitals unprepared. The need to treat patients remotely and with limited resources led hospitals to identify a gap in their operational situational awareness. During the pandemic, Israeli Aerospace Industries helped hospitals to address the gap by designing a system [...] Read more.
The COVID-19 pandemic caught hospitals unprepared. The need to treat patients remotely and with limited resources led hospitals to identify a gap in their operational situational awareness. During the pandemic, Israeli Aerospace Industries helped hospitals to address the gap by designing a system to support their effective operation, management and decision making. In this paper, we report on the development of a functional, working prototype of the system using model-based engineering approach and tools. Our approach relies on domain-specific modeling, incorporating metamodeling and domain-specific representations based on the problem domain’s ontology. The tools practiced are those embedded into the Eclipse Modeling Framework—specifically, Ecore Tools and Sirius. While these technological tools are typically used to create dedicated, engineering-related modeling tools, in this work, we use them to create a functional system prototype. We discuss the advantages of our approach as well as the challenges with respect to the existing tools and their underlying technology. Based on the reported experience, we encourage practitioners to adopt model-based engineering as an effective way to develop systems. Furthermore, we call researchers and tool developers to improve the state-of-the-art as well as the existing implementations of pertinent tools to support model-based rapid prototyping. Full article
(This article belongs to the Special Issue Model-Based Systems Engineering and Product Service Systems Design)
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3 pages, 216 KiB  
Editorial
Acknowledgment to Reviewers of Systems in 2020
by Systems Editorial Office
Systems 2021, 9(1), 11; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010011 - 30 Jan 2021
Viewed by 1533
Abstract
Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Systems maintains its standards for the high quality of its published papers [...] Full article
21 pages, 618 KiB  
Article
Building System Capacity with a Modeling-Based Inquiry Program for Elementary Students: A Case Study
by Amanda M. Cottone, Susan A. Yoon, Bob Coulter, Jooeun Shim and Stacey Carman
Systems 2021, 9(1), 9; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010009 - 26 Jan 2021
Cited by 5 | Viewed by 2550
Abstract
Science education in the United States should shift to incorporate innovative technologies and curricula that prepare students in the competencies needed for success in science, technology, engineering, and math (STEM) careers. Here we employ a qualitative case study analysis to investigate the system [...] Read more.
Science education in the United States should shift to incorporate innovative technologies and curricula that prepare students in the competencies needed for success in science, technology, engineering, and math (STEM) careers. Here we employ a qualitative case study analysis to investigate the system variables that supported or impeded one such reform effort aimed at improving elementary students’ science learning. We found that, while some program design features contributed to the success of the program (i.e., a strong multi-institutional partnership and a focus on teacher training and instructional supports), other features posed barriers to the long-term system-level change needed for reform (i.e., low levels of social capital activation, low prioritization of science learning, and frequent turnover of key personnel). In light of these findings, we discuss broader implications for building the capacity to overcome system barriers. In this way, an in-depth examination of the context-specific barriers to reform in this educational system can inform efforts for future reform and innovation design. Full article
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23 pages, 1109 KiB  
Article
Designing Feedback Systems: Examining a Feedback Approach to Facilitation in an Online Asynchronous Professional Development Course for High School Science Teachers
by Amin Marei, Susan A. Yoon, Jae-Un Yoo, Thomas Richman, Noora Noushad, Katherine Miller and Jooeun Shim
Systems 2021, 9(1), 10; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010010 - 26 Jan 2021
Cited by 6 | Viewed by 3913
Abstract
Many researchers have identified the need for a more holistic understanding of the role of feedback in supporting learning in online environments. This study explores how our design, development, and implementation of an online feedback facilitation system influenced high school science teachers’ learning [...] Read more.
Many researchers have identified the need for a more holistic understanding of the role of feedback in supporting learning in online environments. This study explores how our design, development, and implementation of an online feedback facilitation system influenced high school science teachers’ learning in an asynchronous teacher professional development online course. We then describe teachers’ and facilitators’, i.e., feedback providers’, perceptions of the effectiveness of the system’s features for supporting participants’ learning and engagement. Our work also responds to recent calls for developing a more nuanced understanding of how the complexity of feedback influences learning and the need for more qualitative research on online facilitators’ and learners’ experiences working with new technologies. Results demonstrated that, despite the difficulty of analyzing the complex variables influencing learners’ interactions and perceptions of the feedback system, designing adaptive feedback systems that draw on the principles of design-based implementation research (DBIR) offer promise for enhancing the systems’ contributions to teacher learning. Full article
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27 pages, 4477 KiB  
Article
Hydrostructural Pedology, Culmination of the Systemic Approach of the Natural Environment
by Erik Braudeau and Rabi H. Mohtar
Systems 2021, 9(1), 8; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010008 - 22 Jan 2021
Cited by 1 | Viewed by 2442
Abstract
The subject of this article is the dynamics of water in a soil pedostructure sample whose internal environment is subjected to a potential gradient created by the departure of water through surface evaporation. This work refers entirely to the results and conclusions of [...] Read more.
The subject of this article is the dynamics of water in a soil pedostructure sample whose internal environment is subjected to a potential gradient created by the departure of water through surface evaporation. This work refers entirely to the results and conclusions of a fundamental theoretical study focused on the molecular thermodynamic equilibrium of the two aqueous phases of the soil pedostructure. The new concepts and descriptive variables of the hydro-thermodynamic equilibrium state of the soil medium, which have been established at the molecular level of the fluid phases of the pedostructure (water and air) in a previous article, are recalled here in the systemic paradigm of hydrostructural pedology. They allow access to the molecular description of water migration in the soil and go beyond the classical mono-scale description of soil water dynamics. We obtain a hydro-thermodynamic description of the soil′s pedostructure at different hydro-functional scale levels including those relating to the water molecule and its atoms. The experimental results show a perfect agreement with the theory, at the same time validating the systemic approach that was the framework. Full article
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28 pages, 43084 KiB  
Article
Application of Systems-Approach in Modelling Complex City-Scale Transdisciplinary Knowledge Co-Production Process and Learning Patterns for Climate Resilience
by Burnet Mkandawire, Bernard Thole, Dereck Mamiwa, Tawina Mlowa, Alice McClure, Jessica Kavonic and Christopher Jack
Systems 2021, 9(1), 7; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010007 - 22 Jan 2021
Cited by 1 | Viewed by 3235
Abstract
Literature shows that much research has been conducted on the co-production of climate knowledge, but it has neither established a standardized and replicable model for the co-production process nor the emergent learning patterns as collaborators transition from the disciplinary comfort-zone (disciplinary and practice [...] Read more.
Literature shows that much research has been conducted on the co-production of climate knowledge, but it has neither established a standardized and replicable model for the co-production process nor the emergent learning patterns as collaborators transition from the disciplinary comfort-zone (disciplinary and practice biases) to the transdisciplinary third-space. This study combines algorithmic simulation modelling and case study lessons from Learning Labs under a 4-year (2016–2019) climate change management project called Future Resilience of African CiTies and Lands in the City of Blantyre in Malawi. The study fills the research gap outlined above by applying a systems-approach to replicate the research process, and a Markov process to simulate the learning patterns. Results of the study make a number of contributions to knowledge. First, there are four distinct evolutionally stages when transitioning from the disciplinary comfort-zone to the transdisciplinary third-space, namely: Shock and resistance to change; experimenting and exploring; acceptance; and integration into the third-space. These stages are marked by state probabilities of the subsequent stages relative to the initial (disciplinary comfort-zone) state. A complete transition to the third-space is marked by probabilities greater than one, which is a system amplification, and it signifies that there has been a significant increase in learning among collaborating partners during the learning process. Second, a four-step decision support tool has been developed to rank the plausibility of decisions, which is very hard to achieve in practice. The tool characterizes decision determinants (policy actors, evidence and knowledge, and context), expands the determinants, checks what supports the decision, and then rates decisions on an ordinal scale of ten in terms of how knowledge producers and users support them. Third, for a successful transdisciplinary knowledge co-production, researchers should elucidate three system-archetypes (leverage points), namely: Salient features for successful co-production, determinant of support from collaborators, and knowledge co-production challenges. It is envisioned that academics, researchers, and policy makers will find the results useful in modelling and replicating the co-production process in a methodical and systemic way while solving complex climate resilience development problems in dynamic, socio-technical systems, as well as in sustainably mainstreaming the knowledge co-produced in policies and plans. Full article
(This article belongs to the Special Issue Systems Science)
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17 pages, 3450 KiB  
Article
System Modelling and Analysis to Support Economic Assessment of Product-Service Systems
by Khaled Medini, Sophie Peillon, Martha Orellano, Stefan Wiesner and Ang Liu
Systems 2021, 9(1), 6; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010006 - 21 Jan 2021
Cited by 2 | Viewed by 2614
Abstract
The evolution towards more customer-centric operations within manufacturing and service industries gave rise to novel ways of value creation and delivery such as Product–Service Systems (PSS). PSS integrate tangible and intangible elements to create new values for both customers and providers. Therefore, a [...] Read more.
The evolution towards more customer-centric operations within manufacturing and service industries gave rise to novel ways of value creation and delivery such as Product–Service Systems (PSS). PSS integrate tangible and intangible elements to create new values for both customers and providers. Therefore, a close collaboration is required among various actors in a value network to co-create values towards win–win gains. For companies to keep up with this pace, new decision support tools are needed to accompany PSS engineering and to adjust business models. This need is confronted with the scarcity of PSS-oriented economic assessment models and methods. This paper presents a comprehensive framework for the economic assessment of PSS. The framework relies on a novel combination of system modelling and analysis approaches to enable cost and revenue attribution to different actors in a value network. The applicability and relevance of the framework are demonstrated through a case study in the industrial cleaning sector. Full article
(This article belongs to the Special Issue Model-Based Systems Engineering and Product Service Systems Design)
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17 pages, 1819 KiB  
Article
Reduction of Cost, Energy and Emissions of the Formalin Production Process via Methane Steam Reforming
by Jan Puhar, Annamaria Vujanović, Peter Awad and Lidija Čuček
Systems 2021, 9(1), 5; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010005 - 16 Jan 2021
Cited by 3 | Viewed by 3817
Abstract
Production of formalin, which is among the highest production volume chemicals, is highly energy-intensive; thus, reduction of energy use is very important in reducing cost and emissions. The aim of this and its larger overall research is to systemically analyze how to improve [...] Read more.
Production of formalin, which is among the highest production volume chemicals, is highly energy-intensive; thus, reduction of energy use is very important in reducing cost and emissions. The aim of this and its larger overall research is to systemically analyze how to improve sustainability of processes producing formalin as an intermediate or final product. In this part of the work, energy consumption requirements are analyzed for the conventional formalin production process via methane steam reforming, where opportunities for energy consumption reduction are identified. This work will serve as a base case for further investigation of alternative formalin production pathways. To achieve energy savings, heat integration technology by combined pinch analysis and mathematical programming is applied. The formalin production process is simulated using Aspen HYSYS, and heat integration of the production process was performed based on simulated design using GAMS software. Economic and environmental footprint analyses were performed for both non-integrated and integrated designs. Results show that heat integration reduces heat consumption by around 39%, leading to a saving of 11% in capital cost and turning annual operating cost into positive revenue. Heat integration also improves the environmental aspect, where a 7–22% reduction in selected environmental footprints is achieved. Full article
(This article belongs to the Special Issue Selected Papers from SDEWES Conferences 2020)
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15 pages, 3025 KiB  
Article
Modeling Framework to Evaluate Vaccine Strategies against the COVID-19 Pandemic
by Donovan Guttieres, Anthony J. Sinskey and Stacy L. Springs
Systems 2021, 9(1), 4; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010004 - 13 Jan 2021
Cited by 12 | Viewed by 5223
Abstract
SARS-CoV-2, with an infection fatality rate between 0.5 and 1%, has spread to all corners of the globe and infected millions of people. While vaccination is essential to protect against the virus and halt community transmission, rapidly making and delivering safe and efficacious [...] Read more.
SARS-CoV-2, with an infection fatality rate between 0.5 and 1%, has spread to all corners of the globe and infected millions of people. While vaccination is essential to protect against the virus and halt community transmission, rapidly making and delivering safe and efficacious vaccines presents unique development, manufacturing, supply chain, delivery, and post-market surveillance challenges. Despite the large number of vaccines in or entering the clinic, it is unclear how many candidates will meet regulatory requirements and which vaccine strategy will most effectively lead to sustained, population-wide immunity. Interviews with experts from biopharmaceutical companies, regulatory and multilateral organizations, non-profit foundations, and academic research groups, complemented with extensive literature review, informed the development of a framework for understanding the factors leading to population-wide immunity against SARS-CoV-2, in particular considering the role of vaccines. This paper presents a systems-level modeling framework to guide the development of analytical tools aimed at informing time-critical decisions to make vaccines globally and equitably accessible. Such a framework can be used for scenario planning and evaluating tradeoffs across access strategies. It highlights the diverse and powerful ways in which data can be used to evaluate future risks and strategically allocate limited resources. Full article
(This article belongs to the Special Issue Systemic Thinking in Times of the COVID-19 Pandemic Crisis)
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19 pages, 381 KiB  
Article
Requirements for Model-Based Development Process Design and Compliance of Standardized Models
by Avi Shaked and Yoram Reich
Systems 2021, 9(1), 3; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010003 - 12 Jan 2021
Cited by 3 | Viewed by 2798
Abstract
The planning of system development efforts is crucial to the successful realization of projects. However, development planning typically lacks systematic, engineering discipline, and consequently risks project and business success. Model-based process design is a potential information systems approach to addressing the increasing complexity [...] Read more.
The planning of system development efforts is crucial to the successful realization of projects. However, development planning typically lacks systematic, engineering discipline, and consequently risks project and business success. Model-based process design is a potential information systems approach to addressing the increasing complexity of such planning. We characterize the ontology of development process design, based on real-life observations and scientific publications. We then synthesize the required ontology with the desirable characteristics of models, and derive key requirements for model-based development process design. Next, these requirements are used to evaluate the adequacy of three prominent, standardized model-based process design approaches—BPMN, OPM and SPEM. The findings reveal that the surveyed models are a partial fit, and do not promote sound process design. Finally, by generalizing the categorical evaluation results, possible root causes for the identified inadequacies are proposed. A new model design, which should rely on the formulated requirements set, is called for, in pursuit of a wider adoption of model-based design paradigms and better information systems realization to support the development of complex systems. Full article
(This article belongs to the Section Systems Design)
23 pages, 2214 KiB  
Article
Will There Be Enough Water? A System Dynamics Model to Investigate the Effective Use of Limited Resources for Emergency Water Supply
by Lisa Bross and Steffen Krause
Systems 2021, 9(1), 2; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010002 - 08 Jan 2021
Cited by 3 | Viewed by 2801
Abstract
The increased probability of occurrence of various hazards to water supply systems due to climate change requires the strengthening of their resilience through effective emergency preparedness planning. This paper introduces a method for the assessment of the resilience of water supply systems, including [...] Read more.
The increased probability of occurrence of various hazards to water supply systems due to climate change requires the strengthening of their resilience through effective emergency preparedness planning. This paper introduces a method for the assessment of the resilience of water supply systems, including emergency supply measures. With 20 uniquely defined emergency situations, the technical constellations for possible impairments of the water supply are documented. The system analysis developed for each emergency situation is then used to determine and prioritise all suitable supply measures to reduce the supply deficit. Based on the data of a water utility close to Frankfurt, Germany, the developed system dynamics model was used to examine the resource utilisation for the respective emergency situations and to estimate the amount of water provided. The model allows us to scrutinize and compare emergency water supply measures as well as to identify required resources. Furthermore, the method helps us to prioritize measures as well as to make decisions when planning and providing emergency water supply (EWS). Full article
(This article belongs to the Special Issue Engineering Resilient Systems)
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11 pages, 6225 KiB  
Letter
Systemic States of Spreading Activation in Describing Associative Knowledge Networks: From Key Items to Relative Entropy Based Comparisons
by Ismo T. Koponen
Systems 2021, 9(1), 1; https://0-doi-org.brum.beds.ac.uk/10.3390/systems9010001 - 23 Dec 2020
Cited by 4 | Viewed by 2494
Abstract
Associative knowledge networks are central in many areas of learning and teaching. One key problem in evaluating and exploring such networks is to find out its key items (nodes), sub-structures (connected set of nodes), and how the roles of sub-structures can be compared. [...] Read more.
Associative knowledge networks are central in many areas of learning and teaching. One key problem in evaluating and exploring such networks is to find out its key items (nodes), sub-structures (connected set of nodes), and how the roles of sub-structures can be compared. In this study, we suggest an approach for analyzing associative networks, so that analysis is based on spreading activation and systemic states that correpond to the state of spreading. The method is based on the construction of diffusion-propagators as generalized systemic states of the network, for an exploration of the connectivity of a network and, subsequently, on generalized Jensen–Shannon–Tsallis relative entropy (based on Tsallis-entropy) in order to compare the states. It is shown that the constructed systemic states provide a robust way to compare roles of sub-networks in spreading activation. The viability of the method is demonstrated by applying it to recently published network representations of students’ associative knowledge regarding the history of science. Full article
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