System dynamics based learning environments: a technology for decision support and assessment

Traditionally decision support systems (DSS) are designed to help the users make better decisions. However, the empirical evidence concerning the impact of DSS on improved decision making and leaning in dynamic tasks is equivocal at best. In this article, we introduce a new type of DSS based system dynamics technology as tool not only to support users’ decision making and leaning but can also provide an effective assessment of the performance and learning as well

Construction of a fuel demand function portraying interfuel substitution, a system dynamics approach

Most of the recent numerical market equilibrium models of natural gas markets use imperfect competition assumptions. These models are typically embedded with an oversimplified representation of the demand side, usually a single-variable affine function, that does not capture any dynamic adjustment to past prices. To remedy this, we report an effort to construct an enhanced functional specification using the system dynamics-based model of Moxnes (1987, 1990). Thanks to a vintage representation of capital stock, this putty-clay model captures the effect of both past and current energy prices on fuel consumption. Using a re-calibrated version of this model, we first confirm the pertinence of this modeling framework to represent interfuel substitutions at different fuel prices in the industrial sector. Building on these findings, a dynamic functional specification of the demand function for natural gas is then proposed and calibrated.

Modeling and Simulation of Multi-tier Enterprise IT System

This paper discusses modelling and simulation of multi-tier enterprise IT system. The layers in multi-tier architecture consist of web layer, application layer and database layer. Entities in the multi-tier system have been abstracted out into 3 categories- consumer, resource and router. Existing modelling and simulation frameworks for multi-tier systems focus on power management or performance of load balancing algorithms. Our framework enables seamless modelling, simulation, and experimentation of a wide range of what-if scenarios in multi-tier systems while encapsulating all the variations that arise due to configuration, composition, design and deployment. As an illustration, we discuss and simulate prediction of bottleneck scenario with results

An Appraisal of Traceability Systems for Food Supply Chains in Colombia

Traceability systems have improved significantly in the last few years in relation to safeguarding food safety and quality. Although traceability is considered to be an effective tool in supporting quality control, the adoption of different traceability systems along the supply chain can bring the drawback of information asymmetry, which affects inventory management. This paper explores adoption alternatives that may facilitate the blend of traceability technologies in the food industry of developing countries. The analysis is based on a simulation model that represents the behaviour of inventory and food quality in the case of the mango supply chain in Colombia. The results show the asymmetries between traceability systems along the supply chain as well as their effects on inventory and food quality

A System Dynamics Approach to Decision-making Tools in Farm Tourism Development

Background: Besides visiting the main tourist attractions in Slovenia, many tourists want to spend their free time in the countryside as well, but the number of farming establishments in Slovenia diminished distinctly in the last years. Objectives: This paper aims to develop a system dynamics model, with the goal to analyse dynamics of the diversification of agricultural holdings into farm tourism activities in Slovenia. Methods/Approach: A system dynamics methodology was chosen to model the diversification in farm tourism. First, we present a basic concept of a system dynamics model with a causal loop diagram. Further, a system dynamics model with different scenarios is presented. Results: The main feedback loops were identified, and the simulation model was used to analyse different simulation scenarios of the transition of farming establishments into farm tourism facilities. Conclusions: The model provides the answers to the strategic questions about the dynamics of transfer into tourist farms, using several simulation scenarios. The transition mainly relies on subsidies, promotion of diversification and the growth of rural tourism, which provides a relevant direction for the development of future incentives

Developing a calibrated discrete event simulation model of shops of a Dutch phone and subscription retailer during COVID-19 to evaluate shift plans to reduce waiting times

The foundational role of simulation is to enable understanding, discovery, development, and operationsof dynamical systems. As such, modeling and simulation professionals intrinsically encounter problemsthat have non-trivial complexity and scale traits. Inevitably the systems they encounter must be modeled,simulated, and evaluated. This panel presents some challenges in attracting talented individuals to pursueeducation and professional careers, continuing education to satisfy the current and future knowledge andpractices while advancing basic and applied research and development in modeling and simulation. Tohighlight modeling and simulation workforce development, panelists share thoughts borne out of extensiveprofessional and academic experiences at Intel®, Oak Ridge National Lab, MathWorks®, and AS

Dynamic simulation of socio-ecological systems: sustainability in Biosphere Reserves

La aplicación de una perspectiva sistémica en la gestión de las Reservas de la Biosfera es importante a la hora de abordar la estrecha relación entre los procesos ambientales y socioeconómicos, así como los potenciales factores limitantes, particularmente evidentes en el caso de sistemas insulares áridos como la Reserva de la Biosfera de Fuerteventura (RBF), Islas Canarias. El desarrollo turístico de la isla ha favorecido la ocupación del territorio por usos antropogénicos, lo que está incrementando la vulnerabilidad del sistema hacia procesos como el sobrepastoreo y la degradación de hábitats naturales que albergan numerosas especies amenazadas. Con el objetivo de elaborar una herramienta que contribuya a un desarrollo más equilibrado y multifuncional de las reservas de la biosfera insulares, se ha desarrollado un modelo dinámico para la RBF, estructurado en 5 sectores: usos del territorio, conservación de la biodiversidad, recursos hídricos, calidad ambiental y socioturístico. El modelo, calibrado con datos del periodo 1996-2011, integra un conjunto de 30 indicadores de sostenibilidad con el fin de evaluar su evolución e interacciones en la RBF a lo largo del tiempo. Los resultados de la comparación de los valores observados con los simulados, así como de las pruebas de verificación aplicadas, señalan que el modelo es capaz de reproducir el comportamiento de este sistema socio-ecológico. Esta herramienta permite realizar un análisis de los cambios recientes y los conflictos entre los principales factores e indicadores, y así convertirse en una herramienta para favorecer una gestión orientada a minimizar esos conflictos y a reforzar políticas de desarrollo sostenible en la Reserva.The application of a systemic perspective on the management of Biosphere Reserves is important to address the close relationships between the environmental and socio-economic processes and to take into account potential limiting factors, particularly evident in the case of insular arid systems as the Fuerteventura Biosphere Reserve (FBR), (Canary Islands). The tourist development on the island is leading to increasing land dedicated to anthropogenic uses, which is emphasizing the vulnerability of this system to other processes such as overgrazing and degradation of natural habitats that host numerous endangered species. In order to elaborate a tool which contributes to a more balanced and multifunctional development of the insular biosphere reserves, a dynamic model for FBR has been developed, structured in 5 model sectors: land use, biodiversity conservation, water resources, environmental quality and socio-touristic. The model, calibrated with data of the 1996–2011 period, integrates a set of 30 sustainability indicators to monitor their changes and interactions in the FBR over time. Results regarding comparison between observed and simulated values and the verification tests applied showed that the model is able to match the behaviour of this socio-ecological system. This decision-support tool allows analyzing the recent changes and trade-offs between the main environmental factors and indicators, thereby facilitating a management aimed to minimize those trade-offs and reinforce sustainable development policies in the Reserve.Este trabajo se ha desarrollado en parte dentro del proyecto: “Herramienta avanzada para la gestión sostenible y el desarrollo de un sistema de información y participación en las Reservas de la Biosfera” financiado por el Ministerio de Industria, Turismo y Comercio, dentro del Subprograma: Avanza Competitividad I+D+i 2010-2012. Ha contado igualmente con el apoyo del proyecto “IDIGEO: Plataforma para la Investigación y Desarrollo de Sistemas de Información Geomática”, MICINN, Convocatoria ACTEPARQ 2009

Understanding resilience of farming systems: Insights from system dynamics modelling for an arable farming system in the Netherlands

Farming systems in Europe are facing economic, social, environmental and institutional challenges. Highly intensive, climate-exposed, arable farming systems like the Veenkoloniën in the north of the Netherlands are particularly vulnerable to many of these challenges. Just in the past twenty years, the Veenkoloniën has lost half of its small and medium sized family farms specialised in cultivating starch potatoes. While starch potato production continues to be stable as the remaining farms are increasing the size of their operation, local stakeholders are concerned that the farming system in the Veenkoloniën is endangered. In this paper we investigate this issue by using a system dynamics simulation model to explore what the potential structures are that could threaten the long term future of starch potato production and to identify leverage points that can enhance the resilience of the system. Our analysis shows that, so far, farmers’ active engagement in a processing cooperative has been an important element to their resilience to cope with economic and environmental challenges. In practice, the cooperative has been able to act as a buffer and stabilise prices for farmers in the region by implementing strategies that increase the value of their products, open new markets and increase starch potato production.publishedVersio