There was an interesting presentation at ISDC 2004 in Oxford. The title was Spatial urban dynamics presented by Peter Sanders and Frank Sanders. They expanded Forresters original urban dynamics model in terms of spatial point of view. While one of us has been studying Geographic Information Systems (GIS) and applying GIS to consumer spatial behavior. Recently we have got some research results, one of which explains how retailers agglomerate in a city, and the other shows one of the method of calculating relative attractiveness of retail areas. In this paper, we make some contribution toward spatial urban dynamics, firstly discussing the importance of the concept of attractiveness in social sciences, secondly showing latest research result on the attractiveness outside of system dynamics field and how to take it into spatial urban dynamics, thirdly making constructive comments on Sanders approach, finally referring to a strong possibility of expanding spatial urban dynamics toward national models and world models.
This paper discusses our project under a three-year research contract with the Japanese Government to gain public acceptance of nuclear facilities in local communities by improving risk communication through a gaming/simulation approach. Evidence suggests that nuclear public education programs are not communicating the critical safety information necessary to eliminate anxiety of people living around nuclear facilities. To most utilities and government, risk communication means persuasion. Based on the findings of our visits to several authorities, municipalities and nuclear facilities in Japan, Sweden, Norway and USA, we built a causal-loop model regarding nuclear risk communication. According to our model, the root cause of the problem is lack of trust, and the leverages are public participation and transparency which can create learner-centered two-way communication environment. THE TREASURE HUNTING, one of our five gaming/simulations for this project, is intended to create such an environment so that local residents may deepen understanding of nuclear risk and build up a mutual trust relationship with disaster prevention experts. After many internal test runs, we have run this exercise six times so far with the nuclear disaster prevention experts and the local residents near nuclear facilities in various parts of Japan. The results have been quite satisfactory.
The focus of this paper is information exploration using alternative utilization models to test how a supply chain responds to demand changes. From the feedback perspective, it is found that the echelon stock policy generates a more complex feedback structure than the installation stock policy; and has different time patterns of inventory adjustment actions. Considering the relative higher cost for small- and medium- size enterprises to adopt advance information technology in our textile supply chain case, this paper further examines the impact of information technology in the echelon stock policy and the installation stock policy. The findings show that information technology investment could be more beneficial for supply chains with the installation stock policy. Finally, this paper mixes the PID controller design concept with the two information utilization models and so suggests further development for information utilization designs.
Organizations are becoming more aware about the importance of economic, financial and risk management aspects of information system security. As a result, the balance between preventive and corrective security strategies must be studied. We understand Preventive Security as the ability of organizations to avoid the impact of an incident and Corrective Security as the ability of the firm to recover from the losses generated by an incident.
This paper presents a model to analyze the Preventive-Corrective security balance. The main objective of this model is to simulate and analyze the impact that two security behaviors (security investments and strategy) can have one a given enterprise environment. After running 54 simulations, some interesting security behaviors called our attention.
System Dynamics does an excellent peer review of articles. This year, eeing the reviewers' comments and suggestions online was especially welcomed feedback. The additional benefit of initiating a dialog with the reviewers was a bonus.
However, there is always room for improvement. Your thoughts and ideas are welcomed to help us continue to improve our peer review process. Please consider joining a dialog at our Boston meeting to further explore the peer review process. Your presence and ideas are welcome.
Some thoughts for consideration are as follows: 1. Need the peer review process start and end so abruptly? Should the reviewer and writer continue the dialog post the society meeting if mutually agreed? Should a reviewer mentor this process? 2. Are there submissions for review that could be enhanced and offered to other venues for publication, and thus improve recognition for the System Dynamics Society? Should a reviewer mentor this process? 3. Could a practitioners develop a business methodology from theory presented in a peer reviewed paper, or could academics proved theoretical underpinnings for a practical approach presented? Should a reviewer facilitate this process?
If you are interested in discussing these peer review ideas or others, please consider joining an informal meeting!
This paper explores Dynamic Unity between Theory U and System Dynamics
as a way to generally illuminate the "blind spot" and create the setting for
presencing. By describing the blind spot as a System Dynamics process with a
model and behavior, it is hoped that Dynamic Unity will facilitate recognition of the blind spot and produce better understanding of social actions. Dynamic unity between Theory U and System Dynamics will facilitate: identification of common assumptions, modeling of the current problem, producing repeatable results through simulation, and discovery of new insights from simulation results. The instance of presencing will remain the domain of social science, neuroscience and others to explain. Using System Dynamics to project policies through simulation, identify emerging phenomenon, accelerate the learning process, decrease dependence on past experience, change mental models into
new insightful beliefs will take us to the threshold of Theory U presencing.
The success of the Polio Eradication Initiative promises to bring the world the benefits of sustained improvements in quality of life (i.e., cases of paralysis and deaths avoided) and saved costs from cessation of vaccination. Obtaining these benefits requires that policy makers manage both the transition from the current massive use of oral polio vaccine (OPV) to a world without OPV and the risks of potential future reintroductions of polioviruses. In 2001, we began a case study on retrospective polio risk management to demonstrate the importance of using a dynamic disease model to correctly estimate the cost-effectiveness of vaccines. Discussions with the CDC about the case study led to an opportunity for us to develop a large model to support the prospective decision making process. This paper tells the story of our journey, emphasizing insights about the requirements for analysts to create tools that really help high-level decision makers.
The development of large software systems using systems dynamics languages has been hampered by the lack of application of, and support for, modern software techniques. Support is needed to handle the challenges of modular system dynamics model development. These development challenges include the handling of namespaces, linking separate modes, and maintaining clean logical separations among components. Most modern software patterns and languages support such a capability. This paper presents an approach to group, large scale, system dynamics model development that has proven valuable in our project. Our approach included the creation of a software tool, called Conductor, to facilitate our group development. The tool, Conductor, is generally applicable to other projects using Vensim®.
Mental models are bases to recognise phenomena and make plans to improve situations. They can be expressed in model builders' natural language. It is also necessary to examine mental models using a computer simulation. The Computer simulation requires expressions, which can be translated into computer codes. Therefore, model builders need to translate their model from their own natural language to simulation-friendly language, i.e. stock flow diagrams in System Dynamics. It is widely recognised that this translation is sometimes difficult not only for people who are beginners of System Dynamics but also for people who are experienced in the field. This paper discusses a possible translation procedure and shows an application of it. The proposed procedure is designed to use a subset of a natural language as an intermediate language. This idea is applicable regardless of variety of natural language.
Today software vendors have various ways to handle their products. In contrast to non-software products, software products' properties can be changed or controlled at a low cost; vendors do not need to extend their operations, and well-designed software can be customized systematically. Moreover, its diffusion is influenced by network externalities. The diffusion structures of software that have single user type, e.g. World Wide Web browsers, can be expressed mainly as a single reinforcing loop. This is because users can be considered as homogeneous. However, there are multiple possibilities of structure, which corresponds to business strategies for software which has divided users. An example in this category would be highly specialized software, e.g. simulation software. We attempt to explain diffusion processes and characteristics concerning network externalities of software in this category using System Dynamics models. This paper shows that multiple editions can more effectively assist diffusion of main products than strengthening network externality effects.