A variety of approaches are being developed to elicit knowledge from clients and develop that knowledge into conceptual maps and formal simulation models. We completed a project that provides a case example where the standard method was adapted for use in a group model-building intervention. We worked with a group of 10 wildlife managers to support system conceptualization, model formulation, and management response to an increase in negative human-black bear interactions in residential areas of New York State. This article discusses the procedural and conceptual steps, insights, and lessons learned from our model building intervention. Our paper focuses on model-building process and learning outcomes, rather than quantitative validation of a simulation model.
Most large development projects suffer overruns and delays, despite substantial effort spent on systems tracking risks and projecting performance. Managers have an especially difficult time making big decisions such as major project re-plans. Typical project management systems have key blind spots that limit their value for comprehensive decisions. Most project management tools are blind to project dynamics variations in productivity and quality over time under different conditions. System Dynamics models have been used to address this weakness and capture project dynamics, but typically these models have their own blind spots as they omit key details. With many pressing decisions and little time, managers rely on intuition to supplement the limitations of management tools. The combination of little time for major decisions, limited tools, and unreliable intuition is a key contributor to the poor results often achieved on major projects. This paper offers perspective on the challenges of making major decisions and describes a case using an integrated management tool -- a System Dynamics model linked to a database of project details. This management system was used to restructure a multi-billion dollar development program with detail and rigor examining dozens of different options, sensitivities, and leverage points in one month.
Studies made by the Swiss politician Jean Ziegler show that the world agricultural system is able to feed twice the population of the planet. However, 800 million people are hungry. During the last years, the Colombian Government has been designing policies oriented to provide solutions to the hunger problem and thus to decrease the number of Colombian families which lack this fundamental right, the food supply. However, the effects of these policies have not been the expected ones, on the contrary, lower class people is still plunged into poverty and hunger. Why have they not been effective? Which have been the consequences of implementing those policies?
Considering the impact of economic liberalization during the 90s on the agricultural sector, a model has been constructed taking into account the national production, the cultivated area, the people working and the capital invested on the agricultural process. The simulation results of the implementation of the commerce liberalization policies seem to match with the results recorded in the Agricultural and Rural development Ministry. Finally, the model will be tested in a scenario that includes the policies that are part of the Development Plan proposed by the current Government 2002-2006 to observe possible consequences of this implementation.
Effective citizenship for the 21st Century calls for young people adept at understanding a world of growing interdependence and multiculturalism. This means new intellectual foundations for understanding complexity and new learning skills for building shared understanding of complex issues like sustainability. Yet most of our schools remain much as they have long been, with sharply demarked subject matters and public education policies that stiffen these disciplinary identities. The result is that even older students have little mastery of understanding of the critical problems shaping their world. New educational outcomes require new educational systems - not just "school systems" in the traditional bureaucratic use of the word but learning communities within and beyond the school that can affect all aspects of children's lives. Peter will share information and invite conversation around current work to develop a network of innovative school systems pioneering a multi-layer view of curricular, institutional and community innovation.
The strategy to recover components from discarded electrical and electronic equipment to obtain spare parts is promising, especially during the final service phase. In that phase, the original product is no longer produced and the sources of new parts are often limited. Controlling those closed-loop supply chains is challenging. Decision makers have to choose when to acquire discarded equipment, when to recover used parts, and when to produce new parts. We developed a generic system dynamics model that provides a test for various proposed policies to control closed-loop supply chains with parts recovery and spare-parts supply.
In banks decisions are made in a speedy and complex environment often with huge uncertainty. This risk must be managed proactively on an enterprise level. To accomplish this task, a systemic view of the bank is essential. Up to now there is no standardised approach for analysing the overall risk dynamics of a bank that is capable of describing the forces inherent in risk management. Most risk models are constrained by their static view, so that they hardly capture the rapid and discontinuous changes. This paper examines the dynamics by applying system dynamics to enterprisk risk management, with the aim of understanding the banks risk dynamics. In order to simulate the risk dynamics of a universal bank a dynamical enterprise risk model was developed. By combining the disciplines of enterprise risk management and system dynamics, this paper shows how a systemic view can improve structures in bank risk management and the need for large system thinking.
This paper proposes a contribution to the domain of systems thinking skills. Empirical studies have repeatedly shown surprising misperceptions and inabilities in subjects confronted with tasks involving very simple stock and flow systems. Here it is proposed to represent these skills as implicit integration, by which Polanyi modeled our ability to know. In this framework, Dreyfus and Dreyfus five stage model of learning is used to construct three hypotheses concerning the learning of systems thinking and its importance for learning from modeling and interaction with models. The tests elaborated by Ossimitz are adapted for this purpose and some tasks are added, to serve in the experimental corroboration of the hypotheses. Since the empirical work is currently under way, only few results can be presented; consequently the main contribution is the conceptual construction of the hypotheses.
The aim of the System Dynamics Model KEYNEO is to model the German economy over a long time period (40 years). Keynesian and neoclassical elements form the base of KEYNEO. In the first step a complex feedback structure was developed to model the main economic variables on an aggregate level. The equations for the supply and the demand side of the economy were defined in the second step.
The results of different runs demonstrate that KEYNEO mimics historic data quite good. With the use of optimization tools the parameters could be estimated. The statistical analysis of KEYNEO shows that the results are highly significant. This verification underlines the quality of KEYNEO to model an economy.
In addition, the structure of KEYNEO may serve as input for much more sophisticated models.
The aim of the System Dynamics Model ESCOT is to describe a path towards a sustainable transport system in Germany and to assess its economic impacts. ESCOT was developed within the environmentally sustainable transport (EST) project of the OECD that was designed to set-up the ecological and technical framework of a transition towards sustainable transportation. ESCOT comprises five models: the macroeconomic, the transport, the regional economic, the environmental and the policy model.
The economic assessment for environmentally sustainable scenarios shows that the departure from car- and road freight-oriented transport policy is far away from leading to an economic breakdown. By expanding the time period for the transition we derived even more encouraging economic results.
For the economic assessment it is important that ESCOT considers not only first round effects but also secondary effects. This ability makes ESCOT a powerful instrument for the assessment of such large system changes.
A system dynamics (SD) model without an instructional overlay is not a sufficient learning tool (Spector and Davidsen 1997, Alessi 2000). We propose Cognitive Load Theory (CLT, Sweller 1988) as a theoretical framework for devising effective instructional context for SD models. Providing a systematic distinction between the several sources of cognitive load, CLT specifies what (and why) should be considered when the instructional overlay for a learning environment is designed. Having developed a simple SD model of the theory, we use it to explore how various instructional choices might impact effectiveness of the learning process. Finally, we consider the CLT recommendations in the context of SD-based learning environments and discuss how they may provide input to developing a set of guidelines for design of effective ways to communicate insights of SD models to a broader audience.