Use Of System Dynamics Research Articles

How Does Organizational Citizenship Behavior (OCB) Affect the performance of megaprojects? Insights from a System Dynamic Simulation

As one of the emerging research fields of sustainability management, Organizational Citizenship Behavior (OCB), especially its influence on project performance, has been drawing increased attention both in the academic and industrial areas. Nevertheless, existing studies mainly examine the static relationship between OCB and project performance but fail to explore the dynamic characteristic of the relationship as a project may evolve and proceed over the time. Therefore, this paper aims to evaluate the dynamic impacts of OCB on the performance of megaprojects with the assistance of a system dynamic model. Four causal feedback loops and a stock-flow diagram were developed to illustrate the dynamic influencing mechanism, and three distinct policies quantitatively simulated the possible impacts arising from the changes of OCB on the whole system and, specifically, on the performance megaproject. The results show that an increase in the AIRPP (actual increasing rate of potential promotion) exerts significant influence on the improvement in OCB and the performance of megaprojects. The higher the AIRPP in the multi-policy scenario, the higher the OCB and the performance. One major contribution is that this study is one of the first studies to explore the potential use of system dynamics to model megaproject organizational behavior and its performance with implications in both the practical and cultural promotion of OCB.

Urban systems complexity in sustainability and health: an interdisciplinary modelling study

BackgroundImproving urban health and sustainability raises complex questions that are best addressed through interdisciplinary and even transdisciplinary approaches, in which scientific research and analysis and stakeholder engagement have important roles. In this study we report pilot work in Nairobi (Kenya) and London (UK) that uses innovative methods to integrate qualitative and quantitative modelling to provide evidence to support policy development for health and sustainability in these cities. MethodsWe used two primary modelling methods, system dynamics and microsimulation, and sought to understand the value of these tools in combination to support policy decisions. System dynamics was used to establish an aggregated and non-linear causal map of the interconnections between diverse variables, and thus to gain insight into the policies and specific processes that need to be examined in further depth. System dynamics was a key tool for city-level stakeholder engagement. In part informed by the outcome of the system dynamics process, microsimulation was then used to quantify local effects on health of selected policy options. The results were mapped using geographic information systems methods. FindingsThe combination of system dynamics and microsimulation models provided a framework that enhanced collective knowledge about the interrelationships of policy decisions, funding, public awareness, and environmental and health effects. Our initial participatory system dynamics work on air pollution in Nairobi found that a combination of policies that focus on households and outdoor air could reduce household air pollution by about 50%, leaving it still above WHO-recommended levels. Yet, the investments in monitoring and health impact assessment have the potential to trigger reinforcing mechanisms that create synergies among existing policies and increase the return on investment. Preliminary 106-year microsimulation runs of the effects of PM2·5 in London revealed that anthropogenic emissions are associated with about 2300 incident cases of ischaemic heart disease annually. The two methods appeared to have valuable complementarity in their focus on aggregated dynamics at the policy level versus local policy effects. InterpretationThe use of system dynamics can produce a quantitative model of the policy implementation process, including the organisational barriers and opportunities for change. This can be extended to include aggregate outputs from other models to quantify a more holistic and high-level quantitative model of the dynamics of selected policy questions. Together, these methods can estimate regional environmental and local health effects of selected policies, but also inform about overcoming the barriers to these policies. FundingThe Housing in Nairobi's Informal Settlements—A Complex Urban System project funded by the Engineering and Physical Sciences Research Council, and the Complex Urban Systems for Sustainability and Health project funded by the Wellcome Trust.

The application of system dynamics modelling to environmental health decision-making and policy - a scoping review

BackgroundPolicy and decision-making processes are routinely challenged by the complex and dynamic nature of environmental health problems. System dynamics modelling has demonstrated considerable value across a number of different fields to help decision-makers understand and predict the dynamic behaviour of complex systems in support the development of effective policy actions. In this scoping review we investigate if, and in what contexts, system dynamics modelling is being used to inform policy or decision-making processes related to environmental health.MethodsFour electronic databases and the grey literature were systematically searched to identify studies that intersect the areas environmental health, system dynamics modelling, and decision-making. Studies identified in the initial screening were further screened for their contextual, methodological and application-related relevancy. Studies deemed ‘relevant’ or ‘highly relevant’ according to all three criteria were included in this review. Key themes related to the rationale, impact and limitation of using system dynamics in the context of environmental health decision-making and policy were analysed.ResultsWe identified a limited number of relevant studies (n = 15), two-thirds of which were conducted between 2011 and 2016. The majority of applications occurred in non-health related sectors (n = 9) including transportation, public utilities, water, housing, food, agriculture, and urban and regional planning. Applications were primarily targeted at micro-level (local, community or grassroots) decision-making processes (n = 9), with macro-level (national or international) decision-making to a lesser degree. There was significant heterogeneity in the stated rationales for using system dynamics and the intended impact of the system dynamics model on decision-making processes. A series of user-related, technical and application-related limitations and challenges were identified. None of the reported limitations or challenges appeared unique to the application of system dynamics within the context of environmental health problems, but rather to the use of system dynamics in general.ConclusionsThis review reveals that while system dynamics modelling is increasingly being used to inform decision-making related to environmental health, applications are currently limited. Greater application of system dynamics within this context is needed before its benefits and limitations can be fully understood.

Dealing with sustainability in groundwater management using system dynamics approach, a case study in Iran

Water is deemed as the most critical resource for life on earth. Cognition of its soaring deficit in some regions has driven endeavors to take immediate and effective actions by water management. In arid and semi-arid areas, where rivers are mostly seasonal and access to surface water is limited, groundwater is the major source of freshwater particularly for agricultural irrigation. Meanwhile, dealing with groundwater resources management is intertwined with sustainable development concepts ending up with a complex and interactive socio-economic system. The primary aim of this study is to demonstrate the usefulness of system dynamics as a decision support tool to model and analyze such a system. Taking an agricultural plain in south of Iran as the case study and simulating the proposed model for 50 years, we intend to observe the long-term impacts of 5 policies to improve the sustainable development indicators through remediation of groundwater level in the studied region. The results show that the policy of combination of budget allocation for conservation education and modification in water tariffs might be more effective in improvement of the target indicators.

Use of System Dynamics to Evaluate Shortening of the Calving-to-Conception Interval in Japanese Black Cattle

Use of System Dynamics to Evaluate Shortening of the Calving-to-Conception Interval in Japanese Black Cattle

Modelling Internal Migration with the Use of System Dynamics

The article provides a detailed analysis of the theoretical basis for the study of labor migration, investigates the preconditions for interregional migration in Ukraine, identifies the effects of expulsion and attraction in different regions, and analyzes their impact on the annual level of migration. On the basis of these observations, the main feedback loops and their interaction were determined, which made it possible to construct a simulation model for the formation of internal migration flows. Based on the constructed model, a scenario analysis was conducted, which found that the level of internal migration is particularly sensitive to changes in the cost of housing in other regions, as well as to the increase of the wage gap in destination regions. The study revealed the main obstacles and opportunities for improving the regulation of interregional migration within the country.Article received 23.05.2017

Strategic workforce planning in healthcare: A multi-methodology approach

This paper presents a description of the development and use of a framework for strategic workforce planning for healthcare at the national level. The framework is called the Robust Workforce Planning Framework, and was developed by the Centre for Workforce Intelligence. The Centre for Workforce Intelligence was a national organisation that delivered workforce planning advice, and was active from July 2010 until March 2016. The Centre was a key contributor to the planning of future workforce requirements for healthcare in England and was primarily commissioned by the English Department of Health, Health Education England and Public Health England, supporting them in national and local strategic workforce planning. The framework involved the use of multiple methodologies, including the development of strategic workforce models based on System Dynamics, and the framework evolved through practise. This paper describes contributions to three areas in the field: healthcare workforce planning models using System Dynamics, the use of System Dynamics to support strategic planning with the integration of multiple methodologies, and facilitated modelling through building and using System Dynamics models in workshops.

Controlling complex policy problems: A multimethodological approach using system dynamics and network controllability

Notwithstanding the usefulness of system dynamics in analysing complex policy problems, policy design is far from straightforward and in many instances trial-and-error driven. To address this challenge, we propose to combine system dynamics with network controllability, an emerging field in network science, to facilitate the detection of effective leverage points in system dynamics models and thus to support the design of influential policies. We illustrate our approach by analysing a classic system dynamics model: the World Dynamics model. We show that it is enough to control only 53% of the variables to steer the entire system to an arbitrary final state. We further rank all variables according to their importance in controlling the system and we validate our approach by showing that high ranked variables have a significantly larger impact on the system behaviour compared to low ranked variables.

How many Medical specialists do Ministry of Health- Sri Lanka need by 2025: Use of system dynamics modelling for policy decisions

The Ministry of Health is the largest health care provider in Sri Lanka in terms of funding, coverage and human resources. Long duration and high training cost of a medical specialist highlights the importance of health human resource planning. Ministry of Health, Sri Lanka has no scientific cadre planning for medical specialists. System dynamics, an analytical modelling approach and a methodology for studying complex feedback systems was used. Two sub models of “need” and “supply” were developed and simulated over a period of 10 years from 2016 to 2025. By December 2015 there were 1860 clinician medical specialists with an average age of 46.8 years, in the government hospitals in Sri Lanka. In the surgical group of specialties the Proposed Training Rate is more than Current Training Rate while in Medical and Paediatric groups and in Radiology, Anaesthesiology, Psychiatry, Dermatology and Hematology Proposed Training Rate is less than the Current Training Rate. In Surgical specilities the number of trainees enrolled in the Pre-MD programme should be increased from 55 to 71 and while in Medical specilaities the number of trainees enrolled in Pre- MD programmes should be reduced from 107 to 68 and in the Paediatric specialities from 47 to 39. During the 2016-2025 period, 765 specialists will be lost to the Ministry of Health costing nearly Rs 7.6 billion and there will be 4050 consultants by 2025, which is a 120% increase.

Policy choices in dementia care-An exploratory analysis of the Alberta continuing care system (ACCS) using system dynamics.

The increase in the incidence of dementia in the aging population and the decrease in the availability of informal caregivers put pressure on continuing care systems to care for a growing number of people with disabilities. Policy changes in the continuing care system need to address this shift in the population structure. One of the most effective tools for assessing policies in complex systems is system dynamics. Nevertheless, this method is underused in continuing care capacity planning. A system dynamics model of the Alberta Continuing Care System was developed using stylized data. Sensitivity analyses and policy evaluations were conducted to demonstrate the use of system dynamics modelling in this area of public health planning. We focused our policy exploration on introducing staff/resident benchmarks in both supportive living and long-term care (LTC). The sensitivity analyses presented in this paper help identify leverage points in the system that need to be acknowledged when policy decisions are made. Our policy explorations showed that the deficits of staff increase dramatically when benchmarks are introduced, as expected, but at the end of the simulation period, the difference in deficits of both nurses and health care aids are similar between the 2 scenarios tested. Modifying the benchmarks in LTC only versus in both supportive living and LTC has similar effects on staff deficits in long term, under the assumptions of this particular model. The continuing care system dynamics model can be used to test various policy scenarios, allowing decision makers to visualize the effect of a certain policy choice on different system variables and to compare different policy options. Our exploration illustrates the use of system dynamics models for policy making in complex health care systems.

Design of a System Dynamics Model to Analyze the Styrene Demand in the Brazilian Market

The growth of the petrochemical industry is based on end-user applications such as the automotive and construction sectors, which are the main drivers of the styrene market. However, the use of substitutes for petrochemicals is a reality and creates a competition in the applications of petroleum products. In this sense, this research aimed to design a system dynamics model to evaluate different scenarios, observing the behavior of the styrene demand over time. In the first phase of the project, a greater understanding of the issue was created and a closed loops diagram was elaborated. It was used during the second phase to design an explanatory regression validation model for the styrene demand. In phase three, a visualizing model and scenarios were designed. The scenarios themselves and the results of each scenario were evaluated. The designed and simulated scenarios aimed to evaluate the impact that the use of substitute materials and the variations in gross domestic product cause to the styrene market. The use of system dynamics together with scenario planning was efficient as different strategies for the market could be evaluated based on the simulated scenarios. A critical analysis of the model’s contribution to the decision-making within organizations concludes the study.

Teaching the Use of Systems Dynamics for Strategic Decision Making in Healthcare

Having worked in the healthcare system and taught healthcare MBAs for over a decade, we have observed that healthcare systems and departments operate in independent silos. This paper shows how to use systems dynamics as a method to help students examine the big picture of how components fit together to form a system. We demonstrate the application of this approach and provide an example from one of our healthcare professional graduate student teams.

Review on Using System Dynamics in Designing Work Systems of Project Organizations

System dynamics research has been introduced to some management fields including operations management, organizational behavior, project management, and market uncertainties research. This paper highlights the use of system dynamics in modeling work system design of projects' organizations seeking better projects behavior. This paper provides a review on system dynamics in product development projects exploring managerial and organizational factors influencing projects' behavior and probability of success. The review includes three different yet intermingling fields; organization's work system design, project management in projects' organizations, along with system dynamics. This paper proposes guiding method to explore how to use system dynamics in projects' work system design and development.

Modeling housing supply and demand using system dynamics

Purpose The housing sector in Egypt represents a considerable share of the gross domestic product (GDP) and accordingly the economy. Further, it is considered vital for any population around the world, because it provides the shelter needed by people. Egyptian housing market is facing many problems which need to be solved. The paper aims to discuss these issues. Design/methodology/approach This research reviews and analyzes the Egyptian public and private housing market’s key variables. As such, it highlights the importance of informed decision making through detailed analysis and study of the market, especially when planning for the future by any housing market stakeholder. The research proposes the use of system dynamics (SD) modeling to analyze the market by creating a stock and flow model using STELLA modeling and simulation software. Findings The results reveal that the expected newly established families will be nearly 800,000 families in year 2015/2016. Out of these numbers, 600,000 families require economic housing units, while the expected supply is nearly 300,000 units. Originality/value A study is made for the economic housing market, which is a very big housing market and population segment that has been suffering from negligence for years.

System dynamics analysis for an Internet-of-Things-enabled production logistics system

A production logistics system is often subject to high operational dynamics due to large working areas, frequent resource interactions, long operation periods and intensive human involvement. Researchers have applied system dynamics to design the structure of statistically robust systems which accommodate common dynamics. Yet this approach begins to lose its feasibility because dynamics anticipation and statistics are becoming more difficult in ever more competitive markets and adjustments to system structure typically incur high costs. In response, this study explores how a robust information structure can be designed and real-time control schemes for controlling the dynamics inherent to real-life systems applied. Motivated by the wide application of industrial Internet-of-Things (IoT) systems, this paper investigates the typical production logistic execution processes and adopts system dynamics to design cost-effective IoT solutions. The internal and external production logistic processes are first investigated separately. Using sensitivity analysis, the optimal IoT solutions are evaluated and analysed to provide guidance on IoT implementation. Internal and external production logistic processes are then combined into an integrated structure to offer a generic system dynamics approach. This research does not only enhance the use of system dynamics, but also presents a quantitative IoT system analysis approach.

Exploring stability and change in transport systems: combining Delphi and system dynamics approaches

Transport is a vast and complex socio-technical system, and despite a clear need to reduce dependence on fossil fuels due to undesirable environmental impacts, it is largely locked into business-as-usual. Systems approaches are a useful way to help make sense of multiple competing influences which may be simultaneously driving change and supporting the status quo. This paper applies qualitative system dynamics modelling to help interpret the results of a Delphi study into global transport transitions, involving 22 international experts in various aspects of transport. The main contribution of the paper is its exploration of the use of system dynamics (SD) modelling to interpret the Delphi findings. SD modelling was used to reveal and elucidate the causal arguments put forward by the expert panel about the factors driving business-as-usual, the factors creating barriers to more sustainable transport systems, and the drivers of change. The SD model is used to explore and expose the key causal patterns at play, and how these interact to both support and hinder change. The resulting model shows the complex, interdependent dynamics involved in supporting the status quo. Even at the relatively high level of analysis reported here, the model is useful in revealing interdependencies between parts of the system, where change in one part may well have knock-on effects elsewhere in the system. In particular the model reveals the strong reinforcing loops that act to minimise the impact of change drivers and thus retain the dominance of automobility. The result is a system that is highly dependent on the continued existence of key reinforcements such as policies that subsidise fossil fuels. From a methodological perspective, the outcomes of the Delphi study provided a rich source of qualitative material which was highly suitable for developing a system dynamics model.

Modelo de dinâmica de sistemas para o processo de S&OP ampliado

Resumo Apesar de o processo de S&OP (Sales and Operations Planning) não ser uma prática nova nas empresas, principalmente naquelas de grande porte, ainda é tema de estudos nas suas práticas e ferramentas computacionais de apoio. Modelos e ferramentas computacionais focadas para o auxílio no processo de S&OP são utilizadas e podem contribuir para a melhoria da qualidade da sua execução e dos seus resultados. As ferramentas mais comuns são aquelas baseadas em planilhas eletrônicas, e as mais sofisticadas, em técnicas de pesquisa operacional inseridas em sistemas APS (Advanced Planning Systems). A partir da revisão bibliográfica realizada sobre teoria e técnicas computacionais usadas para o auxílio do processo de S&OP, foi identificada a ausência de estudos relacionados ao uso de Dinâmica de Sistemas (System Dynamics). Adicionalmente, a revisão aponta a necessidade de estudos relacionados à integração de análise econômica e financeira durante a elaboração dos planos agregados e o uso de variáveis probabilísticas no processo que possibilitem a análise estatística no sentido de fornecer planos mais confiáveis. Outra questão relevante observada é que os gestores que participam do processo de S&OP nem sempre têm uma visão global de todas as variáveis e restrições envolvidas neste processo, assim observa-se também que as técnicas e ferramentas utilizadas para execução do processo de S&OP não oferecem uma visão holística das atividades e variáveis envolvidas. Com isso, neste trabalho, é proposto um modelo de Simulação de Dinâmica de Sistemas que proporcione uma visão holística para o processo de S&OP e que permita a integração com os processos da área financeira e o uso de variáveis probabilísticas. A avaliação dos resultados das simulações realizadas com o modelo, apoiada por um projeto de experimentos (DoE), mostra que os planos gerados são compatíveis se comparados com a prática empresarial, com a vantagem de tratar a análise econômica e financeira simultaneamente e ainda possibilitar a geração de inúmeros cenários de planos de S&OP.

Assessment of Long-Term Effects of Marketing Mix Policies

Understanding of the long term effects of marketing mix policies on firm's financial outcomes is counted as an essential issue in marketing studies. Managers really need to know the efficiency of their decisions in marketing efforts. A large number of researches have been already conducted so as to disclose these consequences, although all of them have got some limitations. In the present paper, the authors have made use of system dynamics to develop a dynamic marketing system and analyze the effect of different marketing mix policies on firm's financial indicators. For this purpose, they have introduced two dynamic marketing models based on the related literature review. The first one, that is a qualitative model, represents the logic of marketing efforts based on system dynamic rules and the second one is a quantitative model which is based on five important loops of the qualitative model. The quantitative model has been manipulated in order to analyze several marketing mix policies (scenarios). The results indicate that decision making for selecting appropriate marketing mix is a complicated process usually leading to nonlinear and complex results. Considering this point, the authors' study suggests the utilization of dynamic simulation in order to predict and analyze the effects of marketing policies on firm's financial indicators. Finally, the findings clearly show the ability of system dynamics in measuring and anticipating firm's marketing initiatives and adapting the most effective policy for its success.

DINÁMICA DE SISTEMAS, UNA HERRAMIENTA PARA LA EDUCACIÓN AMBIENTAL EN INGENIERÍA

This paper presents part of the experience gained in using system dynamics as a tool for environmental education of engineering students from Universidad Sergio Arboleda. From, diverse scenarios that allow students to have a systemic view of the real world and visualize its dynamics, System Dynamics are recreated. Since the environment is a complex system, using System Dynamics favors the identification of nonlinear relationships between the environmental attributes, modeling and extension to other techniques such as understanding the mathematical theory of systems dynamic, thus contributing to the inclusion of environmental issues in a cross-curricular manner, but also allowing the appropriation of the necessary elements in the professional exercise as an engineer. This way, three examples of work with system dynamics are presented which can be implemented with engineering students to introduce environmental concepts that were developed by the research line of Sciences of Complexity and Environment of Universidad Sergio Arboleda, with some of their engineering students. It is concluded that the use of System Dynamics in the teaching of environmental concepts acts as a guideline that connects different fields of knowledge required for understanding the planet's current environmental situation, thus becoming a transdisciplinary tool in engineering.

A managerial application of system dynamics modeling to outsourcing

Purpose – The purpose of this paper is to use modeling and simulation to investigate the puzzling performance problems that plagued the project outsourcing in term of poor quality and delivery delay, and apply the appeal and power of system dynamics modeling as a managerial approach to improve learning and intervention in complex situations to South African context where little or no such attempt had been made. Design/methodology/approach – This work is based on exploratory use of system dynamics modeling to study a web of quality and productivity problems that plagued a company as a result of adopting outsourcing as a policy to bolster productivity and service delivery. Findings – A significant finding from this research is that outsourcing has the propensity to perpetuate any trend it dominantly generates as a result of strong positive feedback loops. It also made explicit the dynamic processes that lead to certain observations that have been made in conventional management literature about the effects of outsourcing. Research limitations/implications – The major limitation to this study is availability of information in form of certain operating data need for calibration thus imposing few aggregations on the model. Originality/value – The authors believe that this work has a degree of originality as it applies system dynamics modeling to public sector outsourcing which not being done before. It also made a significant finding by uncovering possible counteractive effect of outsourcing on internal staff.