|
Conference Proceedings The 13th International Conference of
the System Dynamics Society The following papers were presented at
the conference in parallel and plenary sessions. The original
printed proceedings, edited by Toshiro Shimada and Khalid Saeed, were printed
in hardcopy (Volume I: Plenary Program and Volume II: Parallel Program) and
distributed at the conference. Below please find the Paper Index for these
proceedings, including an abstract. Papers are listed alphabetically by the
last name of the first author. Available papers are Acrobat (.pdf) files and
can be read using Acrobat Reader available from http://www.adobe.com. For details about purchasing a copy of
the printed proceedings, visit our website System Dynamics Society or send an
email message to system.dynamics@albany.edu. PAPER INDEX - listed alphabetically by first author: |
A Search for an Operational Environmental
Policy Based on the "Limits to Growth" Study
Surya Raj Acharya
Khalid Saeed
Abstract: Experimenting further with the World3 model, this paper attempts to formulate the operational means to implement the critical recommendations of the "Limits to Growth" study. Using feedback as the organizing principle and the work of Daly (1991), Page (1997) and Saeed (1985) as guidelines, additional policy space was built into the model for self-regulating its critical policy parameters. The policies so created not only appeared to lie within the scope of the existing and potentially feasible regulatory institutions, they were insensitive to their receptive behavioral parameters and also the timing to intervention. The operational policy design procedures adopted in the paper is also seen to create an important heuristic for policy design in general, which should strive to create operational rather than power-cased intervention.
The Threshold 21: Sustainable Development
Model
Gerald O. Barney
Robert Eberlein
Weishuang Qu
P.D. Sharma
Abstract: As we approach the turn of the millennium and pass the 50th anniversary of the Breton Woods and the United Nations institutions, none of our major development agencies have a comprehensive sustainable development model. The Millennium Institute, after a decade of assisting countries in long-term sustainable development studies, has developed a multidisciplinary national sustainable development model called Threshold 21. The model integrates economic production, national accounts, demography, agriculture, energy, health, education, nutrition, and environment in a single model based on the principles and methodology of system dynamics. It simulates the dynamic interactions of these variables for a period of 50 years. Threshold 21 is written in the Vensim simulation environment. The model is being applied first in an analysis of alternative futures for Bangladesh. The Millennium Institute, in collaboration with development partners, is planning applications in several countries, including Australia, China, and the United States.
Sustainability and lateral Issues: A Model
Nazli Choucri
Rebecca Berry
Abstract: This paper presents the generic framework for a national-level model of sustainability. The basic assumption is that there is not one model (or condition) but multiple possibilities; not one path, but a multiplicity of options. The countries of this world are diverse indeed, and the challenges facing them are both generic and idiosyncratic. In appreciation of the complexity and diversity of development, our approach is to depict underlying structural and functional linkage representing the profile of states, with the objective of exploring possible paths over time in response to structural conditional as well as policy choices.
Formulation Experiments with a Simple
Climate/ Economy Model
Thomas Fiddaman
Abstract: Much of the science and policy debate around global climate change has focused on models. Most models focus is a single aspect of climate change- atmospheric physics and chemistry, macroeconomic effects of abatement policies, or impacts on land cover from changing temperature and rainfall for example. Only a few models attempts to make climate change fully endogenous by including both the influence of human activities on climate and the impact of climate change on human activity. The best-known climate-economy model is William Nordhaus' DICE model. The model is a conventional macroeconomics Ramsey growth model with simple carbon and temperature subsystems added. These create a negative feedback loop which tends to reduce economic output due to climate impacts on economic activity. Experiments with the model suggest that only limited effort should be addressed to carbon dioxide emissions abatement. While the DICE model meets some of the exogenous, such as the growth of population and emissions reduction technology. Output is generated by optimization, rather than by simulation with explicit decision rules. This paper explores the impact of structural changes to the model specification that attempts to bring it closer to the system dynamics paradigm. The impact of exogenous population and the technology drives is explored. Carbon flows are made more explicit, to demonstrate the importance of sink constraints and temperature feedbacks to the carbon cycle. A path dependent energy sector with endogenous technology is tested. Bounded rational decision rules are substituted for optimization. These tests generally yield results suggesting substantially higher abatement levels than Nordhaus concludes are necessary.
System Dynamics and the Sustainable
Development of the Electric Power Industry
Andrew Ford
Abstract: This paper discusses the successful use of System Dynamics in the electric power industry. It begins with a list of studies and articles documenting extensive use of System Dynamics to aid corporate and government planners around the world. I then speculate on why this particular industry has been the focus of so many System Dynamics project for Bonneville Power Administration in the Pacific Northwest region of the United States. Reflecting on the Bonneville project, I observe two important trends. The first is a trend toward interactive models that are easier for group operation. The second is a trend toward more attention on the consumers of electric power. The paper concludes with results from a recent study of the world aluminum industry, an industry that consumes a tremendous amount of electric power.
Systems Thinking and the Case Method
Ari Ginsberg
John Morecroft
Abstract: To create more effective learning environments for a strategic management, system dynamics modelers have recommended the use of computer simulation models as a supplement to conventional case studies. Although custom designed simulation games provide students with the opportunity to investigate the effects of alternative actions, their creation involves considerable development efforts. Moreover, available simulations provide on direction for using case information to discover systems thinking issues and solutions. In this paper we demonstrate how instructors can introduce feedback concepts to students via conventional case discussion. Specifically, we show how feedback processes can be woven into a case discussion involving issues of corporate diversification and restructuring.
Soft Landing into the Twenty- First Century:
The Requirements
Teruo Higa
Abstract: Since the Rome Club published its report. "Limits To Growth", the following have been accepted by the present generations as common goals to create a better world for future generations: the efficient use of our limited natural resources, and the control of the growth of population which shows a tendency to ever consume more and faster. This movement has so far led to variety of revolutionary changes in energy-saving technology as well as the adoption of birth control by governments in Asia, such as China, India, and Indonesia. Since the end of the Cold War, a typical representation of confrontation and competition, the concept of coexistence and co-prosperity have become more viable and acceptable. The goals we wish to accomplish may be difficult, especially, if we proceed with the present method and style of consumption-oriented economic activities and with the burden of an ever growing population. As barriers among nations, economic and otherwise, are being removed, it not only eliminates the conceit of an otherwise isolated nation but it helps to make one nation’s problem a shared and more easily and quickly solvable world problem. As we approach the twenty-first century, people have started accepting the idea of a common goal of creating a world where people thrive towards coexistence and co-prosperity beyond religious, political and ideological differences. In a world of limited resources, desires extravagant and beyond its permissible level would always lead to a state contrary to coexistence and co-prosperity. Therefore, unless we resolve the problem of shortage, we will not be able to firmly establish coexistence and co-prosperity. When we consider the phrase "soft landing into the twenty-first century," it is apparent that we accomplish the following: resolve the problems in our current education system, provide the technology to replace the consumption based economic activities with that of resource-recovery and recycling, and provide fundamental solutions to environment, food production, health care, and energy, all of which are presenting threats to humankind. Our present approach, the application of effective microorganism, has started gaining wide attention as the only technology available now. It has been applied in a wide variety of areas in environment, food production, medicine, energy, and industry. It is expected to be a breakthrough technology promising a soft landing for the people into twenty-first century.
Hierarchical Approach in System Dynamics
Modeling
Dong-Hwan Kim
Jae-Ho Jun
Abstract: Traditionally system dynamists used two kinds of modelling approach; top-down approach and bottom-up approach. With top-down modelling approach (feedback loop thinking) modellers first draw a causal loop diagram and then details it down to the stock and rate variables and then auxiliary. Top-down approach forces a modeller to see forest rather than trees, while bottom-up approach forces a modeller to construct forest by planting trees incrementally. In general, system dynamics use both approach in modelling processes simultaneously or sequentially. However, most of previous softwares for SD modelling have focused on the bottom-up approach. The 'operational thinking' concept of Barry Richmond is most typical in this trend. In this paper, “a hierarchical modelling” is introduced as a new modelling approach which can integrate top-down approach and bottom-up approach. A hierarchical modelling approach extends the sector view concept proposed recently by Barry Richmond. In the hierarchical modelling approach, a sector can contain many sub-sectors which also can have their own sub-sector. A modeller can use a bottom-up approach or operational thinking in a sector. When a modeller wants to connect variable across sector or to extend a variable into a sector, he can use a top-down approach. In this paper, a hierarchical modelling approach is implemented with an object-oriented programming method. This paper explains why an object-oriented programming is necessary in implementing the hierarchical modelling approach and discusses some problems which should be resolved for developing a more easy and transparent hierarchical modelling approach.
Techno-Paradigm Shift and its Research
Methodology
Fumio Kodama
Abstract: In order to express the radical changes in the way technology has been and continues to be developed, applied, and commercialized over time, the concept of a techno-paradigm shift is used. The techno-paradigm shift is distinguished into five dimensions: innovation pattern, and societal diffusion of technology. In order to obtain a comprehensive understanding of these dynamic characteristics of technology, we have to orchestrate a unique blends of scholarly tools- case studies, formal modeling, and insightful observations.
The Folding Star: A Comparative Reframing
and the Extension of Validity Concepts in System Dynamics
David Lane
Abstract: The paper reviews ideas on validation in both mainstream OR/MS simulation and SD. A tetrahedron model derived from the former literature is adapted to SD and proposed in a new form; the Folding Star. This framework structures ideas on the elements of SD activities as well as the roles and validation measures required. Further structuring using a tabular and hierarchical format results in an interpretation of current SD validity test and the proposal of two extensions, concerning cultural and operational issues. The framework is able to demonstrate the validity aspirations of different SD activities and to indicate areas for future development in validation test. It also shows the respective strengths and weaknesses of different SD activities and leads to the proposal of a new form, Extended SD, an engagement between SD and 'soft' OR which aspires to a comprehensive notion of validity.
Managing and Understanding Technological
Innovations
Peter M. Milling
Abstract: Controlling the development of new products, their growth and market penetration is a key task for corporate management. Its importance for the firm's survival triggered extensive mathematical modeling efforts to improve the decision making quality. Most models used in this field, however, lack crucial factors of success or failure of innovation; they frequently do not include managerial decision variable like rice, delivery delays, quality, etc. or do not reflect comprehensively the involved factors. The paper outlines the concepts of computer based Strategy Support and the role of management Simulators. A modularly composed simulation model of the innovation process is presented which reflects the tight interrelationships between corporate actions and market response. In explains how the dynamics of a product life cycle are generated, and how structure causes behavior. The model is relatively easy to understand in its elements and catches essential aspect of innovation dynamics. Its actual complexity results largely from the consecutiveness of the variables and the nonlinear relations. Its applicability to managerial problem solving is demonstrated by analyzing and evaluating different strategies like pricing, capacity expansion and the role of effective quality control. The model is extended to include the processes of Research and development and their relationship to resource allocation and market success. A management simulator- based on the comprehensive innovation model- is introduced which supports teaching and training and fosters Organizational Learning.
Communication Network Systems for
Competitiveness: The Japanese World Class Manufacturing Case
Michiya Morita
Nobuhide Tanaka
Harunori Mori
Yutaka Takahashi
Abstract: The functioning of the communication systems has been thought as one of the most important management and operating processes for the firm's competitiveness. This paper is trying to identify the communication systems' structure which lead to high competitiveness, from the positive analysis of Japanese World Class Manufacturing complains. The "linkage" structure throughout the firm from the strategic or innovative communication phase to the operational communication phase has appeared. We inquire into the determinants of the structure. The process of forming the structure is proposed hypothetically based in the analysis. We also provide the implications for modeling the structure by the system simulation like System Dynamics, the problems to be challenged and potential managerial meanings we could obtain as the result of it.
Models Crossing the Boundaries of Tools
Magne Myrtveit
Abstract: As the filed of system dynamics matures, and the number of available tools increases, the problems related to incompatible model formats consume increasingly large portions of researchers’, educators’, and model users’ time. Manifestations of these problems are many: Researchers may be unable to communicate models because they are using different tool (or different versions of the same tool). Educators face problems distributing models because schools use different tools. Authors have problems including a model disk with their books, as readers use different tools. Similar problems have been experienced with other tools, like word processors and drawing programs. The kind of solutions that are used for transferring documents between word processors can be applied also to system dynamics models. One solution would be to implement a series of model conversion filters in each SD tool. (This corresponds to the way MS-Word may load and store files in WordStar, Word Perfect, Works, and Write format). Another solution would be to define a common standard file format for interchanging models. (This corresponds to formats like plain text and Rich Text Format for documents, and BMP, EPS, GIF, PCX, TIFF, and WMF for graphics.) The latter approach has several advantages. 1) Each software tool need only support one foreign file format, in addition to its native file format. 2) The software tools need no knowledge of each native file formats. The benefits of developing a model interchange file format are many; 1) Models may be stored in a common format (e.g., in libraries). 2) Models may be transferred in a common format (e-mail, diskettes included in text books, etc.). 3) Co-development of models. 4) Easier use of several tools by the same user.
On The Modeling of Sea Power: An Extension
of the Polis Model in a Competitive Scenario
M. Piattelli
R.G. Coyle
Abstract: This paper deals with an extension of the "Polis" model that focuses on the subject of Sea Power. The presentation follows two complementary lines: the simulation of the naval conflict arising from Greek colonization westward during the last millennium BC; the discussion of this model within the general approach to Sea Power adopted by the leading authors in the field, Mahan and Kennedy. The conclusions concern the actual limits of the Polis in modeling Sea Power and further steps in its development. Finally, the main difficulties involved in issues of this kind are briefly discussed.
A System Dynamics Approach to Sustainable
Cities
Michael J. Radzicki
W. Scott Trees
Abstract: The idea of sustainable cities has become central to the concept of sustainable economic development. This paper demonstrates that system dynamics modeling can be effectively used to study the forces preventing the sustainable development of cities. The problems being experienced by cities located in both the less industrialized and industrialized nations are examined, and a slate of current policy prescriptions is described. Simulation runs from a system dynamics model created to examine some of the barriers to the sustainable development of cities are presented and their implications for public policy are discussed.
Chaos from Generic Structures: A Cautionary
Tale
George P. Richardson
Abstract: An elegantly simple and understandable model composed of generic structures is shown to move from damped oscillations to repeated period doubling, leading eventually to chaos. The third order structure contains a balancing loop with a delay and integral control that attenuates as the accumulated pressure gets relatively large. The model and its behavior are so classic and it so quickly converges on its attractor that it may well serve as an ideal structure with which to introduce complex nonlinear behavior and deterministic chaos. Unfortunately, the model contains a subtle error, which, when corrected, destroys in model's ability to exhibit complex behavior. Reflection on these results suggests a number of cautions about modeling practice.
Problems for the Future of System Dynamics
George P. Richardson
Abstract: The field of system dynamics first envisioned by Forrester in 1956 is approaching its fortieth anniversary. It has experienced two significant revolutions: changes in practice wrought by the development of iconographic software and the shift from modeling to improve a process to modeling for the purpose of improving people's mental models (Forrester 1992). Its third revolution---expanding the pool of practicing modelers far beyond the nucleus who have received university training ---has been underway since STELLA hit the schools in the late 1980s. A fourth revolution – moving to the forefront qualitative modeling based on word-and-arrow archetypes---began quietly in the mid 1980s (e.g., Wolstenholme and Ciyle 1983) and exploded on the scene with the publication of The Fifth Discipline (Senge 1990). These resent and ongoing revolutions carry promise and potential pitfalls for the field.
The Organization of Learning in System
Dynamics Practice
Khalid Saeed
Abstract: This paper carefully examines the classical system dynamics practice in the context of human learning process and attempts to explicitly state an implementation procedure that should enhance the use of modeling as a thinking companion at a wide scale. A generic model of learning is used to delineate the principles of conduct of system dynamics modeling. Further, the various activities called for are grouped into a set for four core competencies which are based on four key human abilities. The organizing principles which must be superimposed on the learning abilities to deliver the core competencies are also discussed. A clear statement of the principles of the learning process in system dynamic practice should transform system dynamic modeling from an art learnt mostly through apprenticeship of experts to craft acquired through written word.
John Sterman
Nelson Repenning
Fred Kofman
Abstract: Resent evidence suggests the connection between quality improvement and financial results may be weak. Consider the case of Analog Devices, Inc., a leading manufacturer of integrated circuits. Analog's TQM program was a dramatic success. Yield doubled, cycle time was cut in half, and product defects fell by a factor of ten. However, financial performance worsened. To explore the apparent paradox we develop a detailed simulation model of Analog, including operations, financial and cost accounting, product development, human resources, the competitive environment, and the financial markets. We used econometric estimation, interviews, observation, and archival data to specify and estimate the model. We find that improvement programs like TQM can present firms with a tradeoff between short and long run effects. In the long run TQM can increase productivity, raise quality, and lower costs. In the short run, these improvements can interact with prevailing accounting systems and organizational routines to create excess capacity, financial stress, and pressures for layoffs that undercut commitment to continuous improvement. We explore policies to promote sustained improvements in financial as well as nonfinancial measures of performance.
Graham W. Winch
Abstract: When firms face the possibility of making fundamental change, as opposed to incremental improvements, to maintain their competitiveness, their senior teams face particularly uncertain times. This paper focuses on a system dynamics model that captures that situation of an industry experiencing the switching of its production plans to a new process technology. The model enables the complexity of this situation to be represented, and facilitates a clearer understanding of the expected industry dynamics. The results show that an individual firm facing the up-grade decision must consider the impacts of the change across a number of dimensions, and demonstrates that the point in time along the industry's endemic capacity-building / price cycle may have an important impact on the economics of the decision. The paper is also able to draw some comparisons between this and the other approaches to modelling technology change decision-some comparisons between this and other approaches to modelling technology change decision-making.
Systems Thinking, System Dynamics
Eric F. Wolstenholme
Abstract: This paper attempts to build a coherent picture of the way in which various system problem solving methodologies relate to one another. The work builds on the discussion and views expressed at the 1994 System Dynamics Conference that held at Stirling and expressed in the special edition of the System Dynamics Review entitled "System Thinkers, System Thinking". The underlying premises, assumptions and terminology of a number of such approaches are reviewed, contrasted and summarized. It is argued that, in philosophical and academic terms, System Thinking should be considered as a total framework which subsumes all system approaches to understanding human activity. Further, that there exists a range of System Thinking methodologies which can defined and contrasted by positioning them dependent on the degree of vagueness (to be relevant) and their degree of rigour (to be meaningful). It also suggested that their base position may shift dependent on their area of application. It is hoped that this paper or a derivative of it might be used as a reference by practitioners to explain to end-point users if system methods how their own approached fits into a wider and integrated framework.
Strategic Evalution of Flexible Assembly Systems-Combining
Hard and Soft Decision Criteria
Erich Zahn
Jurgen Greschner
Abstract: The evaluation of investments in flexible assembly system lacks of an appropriate methodology. First a brief review of decision making process regarding complex investments is given. Such decisions have to be made in the tension of hard and soft decision criteria which often produce a dilemma for the decision maker: Considering only short-term effects in terms of hard criteria will usually kill investments proposals. In contrast managers feel the need for the investment but have difficulties to justify their intuitive insights. As a possible solution a System Dynamics based approach is proposed to bridge the gap between rational and intuitive judgment. The approach combines qualitative and quantitative criteria by using a computer-aided step-by-step modelling concept.
------------------------------------------------------------------------------------------------------------------------
Quantifying the Soft Issues: A Case Study in
the Banking Industry
Henk Akkermans
Abstract: Quantification of causal models that contain many so-called “soft” variables is often problematic because so few “hard” data are available to calibrate the model. This paper describes a case study in which different techniques were used to qualify a causal model that contained a number of such soft variables, such as “level of expected customer irritation”, or “effort required to reach branch office”. The case study itself concerned the development of a decision-support system to assess branch office viability of a medium-sized bank. The specifics techniques used for quantification are viability for a medium-sized bank. The specific techniques used for quantification are part of the standard “tool set” of the Participative Modelling (PBM) Method, the synergistic blend of system dynamics and group knowledge elicitation techniques developed by the author in a series of six case studies, of which was the fifth.
An Urban Growth Modeling Based On Urban
Attraction
Toshiaki Aoki
Hajime Inamura
Abstract: There are two main current of urban growth modeling. One is a traditional synthetic growth model using System Dynamics(SD). The other is a regional science model which can determine the location of industry and residence based on micro economics. Although this study basically uses the framework of SD, the principles of micro economics and an aggregated behavior model are introduced in some part in order to make the urban growth models more reliable. The model has four traditional sectors, such as industry sector, population sector, land sector and worker sector. In addition to them, there is a crucial addition of the migration sector which predicts the migration intended for Sendai, Tokyo and other part of Tohoku. Migration based on urban attraction is determined using real data based on an individual utility concept and a multiple regression analysis. The model is applied to Sendai Metropolitan Area for coming 100 years.
Electricity Conservation in Domestic Sector
of Pakistan: A System Dynamics Approach
Javaid Aslam
Khalid Saeed
Abstract: This paper describes the dynamics of supply and demand, price and pilferage, and resources and need of electricity conservation in the Domestic Sector of Pakistan. The dynamic hypothesis of the model is described. Then explanation of system behaviour, through model simulation, is given. The system dynamics treatment of the feedback loops is contrasted with the treatment found in most electric utilities of the world in general and of Pakistan in particular. The flexibility of the technique was extensively utilized in policy analysis and 22 policies were studied, out of which 11 are discussed in this paper. It also shows that electricity conservation is a very complex socio-economic environment, a more complex issue than conservation itself, rather moral than economic, and is not very much in the control of utilities alone. The study provided many insight, e.g. pricing policies are not the cause if the problem, increase in income level may not alleviate pilferage of electricity, conservation may be possible with pilferage control and certain incentives, and resource allocation needs social attention.
Dynamic Model of Purchasing Quality
Anil K. Bajpai
Phillip C.T. Wiley
Abstract: The importance of quality costs and benefits is sometimes not fully recognized by industrial managers, Quality costs money. Industrial managers recognize this and tend to be afraid of spending on quality. But, quality also earns money. Industrial managers may need to be convinced of this fact. Unfortunately, existing publications on the subject do not encourage investment for higher quality. Most of the models about quality improvement costs and even about the cost of achieving the desired level of quality fail to incorporate the benefits of improved quality. This paper describes a model of purchase quality costs and benefits. The purchase quality costs elements are drawn from various standard sources such as the British Standards and American Society of Quality Control (ASQC) publications on purchase quality. The benefits from investing for purchase quality are taken from recently published case studies and reports as well as from our own experiences. The elements of quality related activities of a purchase department are -review of purchase order, capability survey of suppliers and purchase planning. The contribution of each element, starting from estimation of loses due to inadequate purchase quality through to prevention of poor quality are isolated and linked dynamically so that costs and benefits are demonstrated through time. The purchase quality costs and benefits model is developed using the system dynamics modelling approach, and simulated using a computer software package, 'Professional DYNAMO Plus'. The simulated results demonstrate the extent to which prevention investment in purchasing is justified by future earning. It is felt that the model can be a significant addition to course material for training programmes of purchase managers. It allows the user to explore the consequence of different levels, type and timing of investment on profit performance and the delays before profits are increased. It is hoped that the model will serve as useful tool for decision-makers, encouraging them to invest in improvement-related activities.
IGRASP-A System Dynamics Software Package
With Automatic Code Generation Facility
Souvik Banerjee
Mohit Junja
Pratap K. J. Mohapatra
Abstract: In this paper, we describe the feature of IGRASP (Interactive Graphic Simulation Package), a software package developed by the authors, which helps in developing and simulation system dynamic model and which has the facility of automatically developing codes for system dynamic models from their flow diagrams. The package integrates the following four modules :(1) The graphic user-interface module, (2) The automatic code generation module, (3) The simulation module, and (4) The output module. The key to the automatic code generation lies in the dimensional matching of the variable for which the code is generated and the set of variables and parameters which influenced it.
An Educational Dynamic Model for Net Working
Capital Management in a Trading Wholesale Firm
Carmine Bianchi
Abstract: The purpose of this paper is to sketch a dynamic model which may be useful to improve net working capital (NWC) management. This subject is commonly studied through the use of accounting models, which are mainly based on General Ledger data.
Dynamic Modeling for "Products
Portfolio" Management and New Products Launching
Carmine Bianchi
Habib Sedehi
Abstract: The paper aims to sketch a dynamic model in order to support decisions for the allocation of financial (i.e. cash flow provided by current sales) and human resources to Marketing and R&D policies, in order to better manage "product portfolio" and new products launching in an industrial firm. The working hypothesis from which the paper stems is to consider that the strategic control for launching new products and monitoring the path of the old ones along their life-cycles is not only possible through the use of accounting models, but also through dynamic models. Both kind of models indeed can be useful in "product portfolio" management; however, each of them may better satisfy different purposes. More particularly, accounting models (i.e.: those which are mainly based on General Ledger data) may better support some cognitive purpose regarding the management of each product separately without taking in "account" the interrelation influence between new and old products. On the other hand, the use of dynamic model, which is mainly based on non-accounting data, may particularly enable to: improve management learning of the system (as a whole) to be handled; implement a strategic control sub-system of resource allocation to product, drawing more on mental models, personal, personal experience and intuition of the entrepreneur and of management than on accounting data; improve an inter-functional and inter-divisional approach and so a better understanding of trade-off among financial, marketing, production, R&D subsystems and though decisions on "product portfolio" management; point out the different levers on which management may act and evaluate the different effects they may produce in the short and in the long term, so to assess the several possible consequences of managerial decision on the product life-cycle; better evaluate the medium/long term effects of product discretionary costs (Advertising, R&D, Education, etc.) on product cash flows. This may lead to a more integrated monitoring and understanding of the paths that different products may run along their cycle. The above said working hypothesis will empirically be tested in a medium-sized wine producer firm.
The Momentum Of Success: The Role of
Construction in the Thailand Economic Boom
Kathleen Brooke
Abstract: Construction freezes the ratio of industrial to housing area (Forrester, 1969), becoming visible, measurable, evidence of structural change. The Momentum of Success documents economic activities of the construction sector during the Thailand economic boom. An important research protocol was the gathering of both qualitative data, with interview of 75 leaders of industry and government concerning decision-making factors experienced during the boom. The database was analyzed by three system dynamicists as well as by the disciplines of psychology, construction economics, and statistics. The results reveal three patterns of strategic action, with suggested future competencies for business and government in regions undergoing rapid development.
Towards Evaluation of Systems Thinking
Interventions: A Case Study
Steven Cavaleri
John Sterman
Abstract: Recent innovations in systems thinking have fueled growing interest among managers in the practical application of the tool (Senge 1990, Morecroft and Sterman 1994, Senge et al. 1994). A number of technologies and protocols are more useful for developing systems thinking capability in organizations and individuals, such as management flight simulators, experiential exercises, and casual loop diagramming. Although various intervention techniques that fall under the rubric ' systems thinking' have become quite popular, little is known about their effectiveness in enhancing organizational effectiveness or productivity. In general, the relationship between the use of systems thinking and organizational performance remains the province of anecdote rather than developed if we are to build a strong foundation for the effective use and refinement of the tools of system dynamics and system thinking. In this paper we evaluate a well-known and often-cited systems thinking intervention in an organization. The evaluation suggests the intervention did have positive effects on the organization, but because the original intervention was not designed with evaluation in mind, the study also illustrates many of the difficulties encountered in conducting such evaluations.
Strategic Modeling for Competitive Advantage
R.Y. Cavana
R.D. Hughes
Abstract: This paper provides an interim report of the work of the authors in developing a framework for analysing strategic and policy decisions within organizations. To explore frameworks a system dynamics model is developed which draws upon Michael Porter's approach to assessing industry profitability, Alfred Rappaport's method for measuring value creation and Oliver Williamson's approach for aligning management structures with the nature of the service being provided that promote economic efficiency. The framework is empirically tested based on the development of a dynamic simulation model of subsidiary of a large private sector company in New Zealand. A number of scenarios are provided illustrating the use of the model.
A System Thinking Approach to Select Avenue
of Science & Technology Development
Jin Chen
Xu Qingrui
Shao Shaomin
Abstract: It is a very important issue for China's sustainable development of economy and society aided by Science & Technology (S&T) Development. The Avenue of Science & Technology Development (ASTD) occupies a special place in the development process of Science and Technology. In Western views, innovation goes through from basic research, technological development to the commercialization. But for most developing countries, as we understood, innovation often started from the process of technology acquisition and innovation occurs when the indigenous technological innovation capability is good. So the S&T development of China may take avenue as NICs did, and improving indigenous technological innovation capabilities is extremely important, but China's strong S&T potentiality should not be ignored, there do exists a special strategy of S&T development for China. Concerning the vague understand on the choice of avenue of science and technology development in China as well as the avenue of science and technology development did not match with national situation of China, this paper provides a system thinking tool, a system dynamics model, to analyze the choice of avenue of science and technology development in coming 50 years in China.
A Conversion Table of DYNAMO into STELLA II
Thomas D. Clark
Hironori Kurono
Abstract: Although there have been many System Dynamics models written in DYNAMO, which are the common property in the society now, there are many obstacles recognized in studying these models using STELLA. This paper shows a conversion table of the basic DYNAMO rules into STELLA II in order to overcome these obstacles. First, we refer to the recent graduate increase of the papers System Dynamics Review, etc. which used STELLA I or STELLA II, and then we expect STELLA II for windows will be used more for model building in the future. Second, we refer to the general features of five differences between DYNAMO and STELLA II in terms of terminology, an equation, a time script, a time related character, and the relationship of Level and Rate (or stock and Flow), and then we refer to one similarity in terms of value chain. Third we show a comparison table of DYNAMO functions with STELLA II functions according to the categories of Delay and Smooth Functions, Logical Functions, Table Functions, and then we show a conversion table of DYNAMO functions into STELLA II functions using simple examples respectively. In addition, we show the applications of Sub-Model and Space Compression Object (SCO) of STELLA II functions, which are the new methods available in Stella II (Mac v3.0.4, 1993). In conclusion, we successfully convert the model of Saturday Evening Post written in DYNAMO (Hall 1973) into a model in STELLA II according to these our findings in order to estimate them.
System Dynamics Modeling of an Activated
Sludge Plant
Bhakta Das
Manas Bandyopadhyay
Pratap K. J. Mohapatra
Abstract: This paper systematically presents, with the help of flow diagrams, the development of a system dynamics model for an activated sludge plant which is used to treat the waste water biologically under aerobic conditions. Three different physical flows (hydraulic flow, biomass flow and flow of substrate) are considered in the model. The model is simulated with the help of IGRASP. The transient and steady-state behaviour of the growth of biomass, sludge production and the treatment efficiency, and their sensitivity to variations of physical (both environmental and physical) parameters are studied in detail. Strategies for recirculation of activated biomass in the treatment plant are evaluated. At the end, the paper indicates the merit of system dynamics modeling as a tool for conceptualizing relationships, integrating knowledge about separate parts and evaluating control strategies in environmental systems.
From Control to Chaos: A System Dynamics
model of Interpersonal Communication
Julia Di Stefano
Abstract: The current interest in learning organizations makes clear the need for more open, more collaborative communication practices in the workplace. "To compete in today's fast moving business environment," says one corporate communication expert, "organization must create a culture of shared understanding" (Locke, 1992,245). However, a major obstacle to facilitating open communication and the generation of new ideas required in learning organizations is the inadequacy of traditional communication models. These models tend to use information for control in organizations; to see information as signals or bits separate from meaning; to see the brain as analogous to a computer; and to seek accurate transmission and replication of messages rather than creation of new information. The purpose of this paper is to show that the confluence model of negotiating differences in interpretation is better suited to understanding interpersonal communication than the traditional cybernetic and information theory models based on Wiener and Shannon and Weaver. Furthermore, it argues that information for control is an outdated model that binds us to old scripts, to replicating traditional patterns rather than creating new ones.
Simulation of Systems Archetypes
Anne M. Dowling
Roderick H. MacDonald
George P. Richardson
Abstract: In recent years an important component of the research agenda in the field of system dynamics has focused on the definition and use of archetypal structures. Although the primary objective of such research is to develop an intrinsic set of system structures that can be used to categorize insights in dynamic systems, the ultimate goal is to provide an effective mechanism by which information can be transferred from a system dynamics model to a client in an easy to comprehend manner. To date, a number of archetypal structures have been presented by Richmond, Senge, and Wolstenholme. This paper discusses two systems archetypes proposed by Senge: "shifting the burden" and "fixes that fail." By developing sets of precise code and simulating the models, the authors document the written descriptions of these two archetypal structures and explore the extent to which the structures behave as expected. The authors demonstrate that the development of formal models for systems archetypes is not an easy task.
Information Age Accounting: Catalyst and
Enable of the Self-Organizing Enterprise
Morton Egol
Abstract: A paradox of the Information Age is that while the sheer quantity of data and information has grown exponentially, the quality of understanding is typically declining. New technologies are driving accelerating change and complexity, leading to greatly increased uncertainty and heightened business risk. There is widespread recognition that the old "command and control" decision making model, which relied on the insights of the "brains at the top" of the organization, is inadequate to cope with today's challenges. Yet nothing has emerged to take its place. Management has responded to change by reengineering core processes and decentralization through "empowerment" of employees and cross- functional teams; but such efforts, while a step in the right direction, have generally not been successful. Instead of increasing the organization's capacity for creative and timely response to radical change in the marketplace, the changes frequently have amounted to mere downsizing- leaving the organization and its employees more anxious and fearful of change than before.
Sustainable Civilization: Cohesion, Capacity
and External Contacts
Tom Forest
Abstract: Human civilizations cover the Earth. In the last several thousand years, many civilizations have been created. Several still exist. Over the next few hundred years, they will change. The most likely scenarios are: 1) All current civilizations come to a quick end in conflict with each other. After several hundred years, new civilizations arise. Many have values and policies strongly contrasting with those of today's civilizations. 2) A new civilization is formed from a combination of today's, which then collapses in civil disorder. After a few hundred years, new civilizations arise, many with values and policies strongly contrasting with those of the world's current civilizations. 3) Today's existing civilizations coexist peacefully until they, in turn then together, dissolve in civil unrest. After a few hundred years, new civilization arise, many with values and policies strongly contrasting with those of the world's current civilizations. 4) Today's existing civilizations change their values, over a course of a few decades, to embrace values of sufficiency and sustainability. They coexist peacefully until, in a few hundred years, they coalesce into a new civilization. This paper describes a model to stimulate the characteristic behavior modes of one civilization's extent and intensity, and how it relates to a second civilization. These modes include externally generated pressure collapse; internal loss of cohesion and resource shortage collapse modes; and a mode of sustainable civilization.
Assessing System Dynamics Curricula: Past,
Present and Future
Susan L. Ganter
James K. Doyle
Micheal J. Radzicki
Abstract: Many claims have been made for the efficacy of the growing number of curricula utilizing system dynamics. However, although there is educational research that will likely support these claims, systematic efforts to document them thus far have been inadequate or non-existent. This paper will review and critique one such effort to assess the effectiveness of system dynamics in the classroom. The compelling need for improved SD assessment procedures, as well as recommendations for the future projects in SD assessment, will then be discussed.
Economic Lift-Off, Boom and Bust: A System
Dynamics View of the Bangkok, Thailand Economy 1980-1992
Peter J. Genta
Donald A. Seville
Abstract: The World Bank has recently published a 390 page study, "The East Asian Miracle" to try to shed some light on the role of government intervention in the development of East Asian economies. Could we better understand this phenomenon participate in an extensive study into the factors behind the Bangkok, Thailand real estate economy, we developed a casual loop diagram to help explain the factors responsible for the boom and eventual slow down. This process revealed some of the leverage points a similar process of understanding, the lessons learned should be applicable to other developing nations.
Nicolas C. Georgantzas
James S. Fraser
Elvan Tugsuz
Abstract: A firm's end-product waste problem motivated us to investigate the structure underlying a polymer coating process (PCP) by combining system dynamics simulation modeling with statistical process control (SPC). Our bipartisan approach proved to be rather powerful: not only it provides insight about the negative feedback-loop structure between temperature distribution and polymer thickness but also allows assessing the potential affects of leverage points on the stability of the polymer manufacturing process directly from the process capability and control charts. The new knowledge gained yields a dramatic improvement in the firm's end-product quality and productivity. Worth nothing is our transforming of the heat control equations--which correspond to the gelling operations of polymer foam and be solved using standard Runge-Kutta methods. Consequently, our essay illustrates how to effectively handle parabolic partial differential equations using conventional system dynamics simulation software.
Allocation Dynamics of Resources Imperiled:
AACSB, Students and Professors
Nicolas C. Georgantzas
Sharon P. Smith
James S. Fraser
Abstract: To comply with accreditation standards of the American Association of Collegiate Schools of Business (AACSB), B-schools in the United States have to maintain a low student to faculty ratio. AACSB standards also affect the process of reviewing full-time faculty (FTF) members for promotion and tenure (P&T), so that the P&T review process safeguards the continued development of educational and intellectual activities in US B-schools. AACSB requires the FTF of its members to enhance the reputation of their B-schools through research and publications. This essay extends the work of Georgantzas, Hamilton, & Drobnis (1994) on the implementation of AACSB standards through feedback-loop planning, showing how a system dynamics simulation model complete with computed scenarios has been helping a small but prestigious B-school assess its future in term of student to faculty ratios.
Nicolas C. Georgantzas
Andreas Schulte
Abstract: This abstract extends the merger and acquisition (M&A) model of Georgantzas, Schmid, & Walton (1994), showing the dynamic evolution of markets into hierarchies or other transactional exchange governance (TEG) forms resulting from the creation of a climate of trust and its effect on the internalization cost of control. The extended M&A model offsets the shortcomings of transaction cost economics (TCE) and points to the potentially rich contribution of system dynamics to exploring governance structures beyond the ideal-type forms of markets and hierarchies that dominate the TCE literature.
An Integrated Social Fabric Matrix /System
Dynamics Approach to Policy Analysis
Roderic Gill
Abstract: All socioeconomic systems are characterised by a complexity of interacting influence patterns that would usually incorporate institutional, environmental, technological, and behavioural relationships. The challenge for management is to develop a sufficiently detailed understanding of these influences in order to develop effective opportunities and mechanism for control. This challenge is heightened by the tradition of 'partial' or non-holistic thinking that continues as the conventional wisdom in the management field. Though the imperative for holistic thinking is intuitively supported by most mangers, the difficulties associated with implementing these ideas into management practice may be perceived as being 'too hard' or 'open ended' for practical application. System dynamics modelling is an appropriate process for developing an holistic understanding of any socio economic system. A realistic model can be applied to the development of management strategies and decision support. To a novice modeller, however, model construction can be intimidating process lacking in the kind of systematic procedural support seemingly offered by the more conventional, non-holistic management school. To a large degree, the integration of the qualitative social fabric matrix with quantitative system dynamics presents a more system modelling process for practical application. The proposed amalgamation also yields some added conceptual insights into the nature of management processes and prospects for control.
Planning Sustainable Agro-Ecosystems: A
System Dynamics Approach
Roderic Gill
Abstract: The assessment of and planning for agricultural system sustainability is a difficult task not adequately handled by conventional methods of farm management analysis. Sustainability is appropriately considered as multi-dimensioned phenomenon incorporating ecological, economic and sociological aspects. An holistic perspective is necessary to consider these dimensions. The inherent complexity of real world agricultural system implies an inductive, rather than deductive analytical approach. As an inductive modelling procedure, system dynamics is able to represent the underlying feedback processes that define those ecological economic processes relevant to an understanding of sustainability. Through such an understanding, the analyst is able to facilitate change towards the ultimate goal of holistic system sustainability. A case study model is developed to indicate the relevant modelling procedure and outline some guidelines for interpretation.
Martin U. Grobman
Abstract: The process of research and development (R&D) in the pharmaceutical industry has become increasingly unproductive during the last few decades. One reason, among others, for this development is the diminishing level of performance reached by research technologies. In the following study the term 'performance' is limited to an output measurement which is reflected by the number of new drugs launched into the market by which therapeutic improvements can be realized. The purpose of this study is to analyze the decreasing performance of traditional technologies in order to partly explain the reduction in R&D productivity. Subsequently, the potential impact of new technologies upon research performance will be simulated by using System Dynamics. Broad-scale random screening is the main technological process traditionally used to discover chemical substances for new drugs. This study reveals the random screening can be adequately modelled by the statistical formula Poisson function. The function is used to calculate the probability of discovering new drugs. Empirical data from the German pharmaceutical industry from the 1950s onwards were out into the formula. The results show that the probability of discovering new drugs has decreased strongly by using random screening. Furthermore, the risk involved in research with random screening can be measured by Poisson distribution functions. In can be seen that risk has risen significantly since the 1950s. The Poisson formula also provides a formal framework for forecasting the impact of new technologies on the rate of drug recovery. The high potential performance of new biotechnologies, especially genetic engineering, could increase research success rates significantly. A System Dynamics model has been constructed in a prototype version to generate scenarios for future output rates. The high uncertainly in predicting research successes can be estimated by a best, a worst and an intermediate forecast based upon varying assumptions. The software application Vensim has been used for modelling and simulating. The model is partly based on hypothetical data and is, therefore, a first step towards forecasting the impact of genetic engineering on research performance in the pharmaceutical industry.
System Dynamics Simulation Software--Dynamox
Jiuqiang Han
Guoji Sun
Abstract: The purpose of this paper is to present the characteristic, functions and program structure of system dynamics simulation - DYNAMOX that can be used on XENIX operation system. This software is mainly composed of six parts. (1) dispatch management module, (2) parameter modify module, (3) model compiler module, (4) model run module, (5) database access module, (6) model library access module. In order to illustrate out software, we give a simple example about the organism relationship model between deers, beasts and grass in Kaibab plateau.
Programs To Support the Development of
System Dynamics-Based Curricula
John F. Heinbokel
P. Jeffery Potash
Martin Engelken
Robert Green
Abstract: Over the past several years, faculty at Trinity College have engaged in a number of project to develop their modelling skills, to incorporate modelling into established courses, to use modelling as foundation for new interdisciplinary courses, to develop modelling skills in our students, and to reach out to pre-college educators to support their development in similar directions. Our more successful experiments share at least one common element: They begin with a conceptually simple theme, and then systematically and progressively build complexity, realism, and connections to more diverse fields, around the central theme. Such structure allows the development of entire course on foundation of system dynamic modelling, rather than episodic modeling exercises common in many other educational settings. An additional benefit is that several of our experiments have begun to provide unexpectedly reinforcing support for other experiments. In this contribution we briefly describe these recent experiments which, together, can provide significant support to pre-college educators and educational systems seeking to enhance the system dynamic components of the curricula. Our efforts to provide initial modeling training for teachers rested upon a graded sequence of modeling exercises progressively developing more complex, realistic models of human population growth, then connecting the population dynamics to the other topics of interest to the teachers. Recognizing this strategy as an effective one for building modeling skills, we have used it as conceptual foundation for an interactive computer-based tutorial for the building of STELLA II models. This Tutorial can support independent learning of this language, serve as a self-paced adjunct to more traditional modeling instruction, or provide a means to convey basic skills and concepts to students using models within a particular course. Following these successes, we developed in 1993 an interdisciplinary (primary biology, history, and economic) college course (Plagues and People) in which a simple model disease transmission served as the core model with which to develop diverse scenarios addressing historical, social, and economical factors of disease in setting ranging from ancient Greece to the modern case of AIDS. A more recent course was based on initially simple models of human population growth and explored how human population dynamics have influenced migration and settlement patterns, was and conquest, resource exploitation, disease, and development pf social and economic systems.
A Mathematical Definition System of System
Dynamics
Jia Ren'an
Abstract: This essay provides a mathematical definition of the causal diagram and the flow diagram. It also elaborates the idea that the level-rates system is the key to solving the problem in System Dynamics. The essay will make a combination to the knowledge of model conceptualization and formulation and improve modeling practice.
System Dynamics Model for A Mixed Strategy
Game Between Police and Driver
Dong-Hwan Kim
Doa Kim
Abstract: Game theorists have recommended lots of reasonable strategies for resolving domestic and international policy problems. In general, they use a concept of equilibrium strategy for analyzing dynamic consequences of available policy options in game situations. One of the most famous policy recommendations suggested by game theorists is that of George Tsebelis (1989). He contends that an increase in penalty against law-violation is not a viable policy tool for decreasing the violation tendencies of drivers. That is because the interactions between police and drivers can be best represented as a mixed strategy game in which each player choose their alternative actions with a probability. In a mixed strategy game between police and driver, the probability of driver's law-violation cannot be decreased by increasing penalty against law-violation. Tsebelis's suggestion seems to be contradictory to common sense. For most policy makers, an increase in penalty is conceived as one of the most effective tools for policy implementation. In Korea, the increase in penalty have vastly reduced the number of drunken drivers. In many countries, the penalty management is a major policy implementation tool for inducing compliance from the people. Our SD model for a mixed strategy game shows that it takes a very long time for an gametheoretic equilibrium to appear. Therefore, game players cannot and should not depend on the equilibrium state for choosing their actions. Furthermore, our mixed game model shows that an increase in penalty can induce a compliance from the people. Our model shows a behaviors which are contradictory to the game theoretic solution, but consistent to the real world behaviors. We have proposed that these gaps between SD model and a game theory come from the ambiguous conception of equilibrium state and the lack of dynamic and transient behavior analysis in the game theory.
Dong-Hwan Kim
Abstract: Traditionally, feedback loops have been analyzed in two ways. First, as in causal loop analysis, the positive or negative relationships between variables are summed up to judge the polarity of feedback loops. This approach can be said as a qualitative method. Second approach for analyzing feedback loops are analytic methods mainly developed for dealing with linear models. For the problems of understanding the behavior of feedback loops, the qualitative methods and analytic approaches give little help to modellers. In this paper, third approach for understanding the behavior of feedback loops are suggested. That is a loop by loop simulation method for tracing the feedback loop gains. First parts of this paper explain the concept of feedback loop gain and the loop simulation method. Second parts of this paper experiment the loop simulation method with two S.D. models; the commodity cycle model which shows equilibrium forces and the two shower model which shows fluctuating system behaviors without external shocks. Last parts of this paper discuss about the dangers of understanding S.D. model with qualitative analysis of causal loops and raise a question on the way of interpreting cyclic or chaotic behavior as shifts in dominant feedback loops.
Transport Forecasting Based on Artificial
Life Concept
Kishi Mitsuo
Hosoda Ryusuke
Yamada Tomoki
Funahashi Hiroki
Abstract: A system dynamics model based on Artificial Life (AL) concept is proposed for transport forecasting. The proposed model focuses on the economic behaviour which emerges out of the interactions among individual local objects, i.e. economic units. That model is merely a large aggregation of simple programs which specify how that local object react in the environment. Application examples are provided to illustrate the applicability of the proposed model.
System Dynamics Model of the Tokyo System
Takahiro Kojima
Yutaka Takahashi
Kinya Machida
Teiichi Igarashi
Abstract: Tokyo and the surrounding region support a huge population. The resulting large number of people who commute to the city centre has necessitated the ongoing construction and maintenance of a vast railway network. Currently transportation form terminal stations to the city centre is provided mainly by Japan Railways' Ymanote Line, the TRTA and the Tokyo Public Subway. Thirteen lines, including those in only partial operation, comprise the subway system in the downtown area. The TRTA forms the heart of the system with nine lines, while the Tokyo Public Subway is relatively small in scale, with only four lines. The current research project provides the TRTA material for use in developing future management directions by data provided by the TRTA. This paper covers the first phase of this research.
David Lane
Abstract: Managers involved in the refining and trading of oil had conflicting views on the relationship between output and cash generation in their market. A day by day account is given of a project in which the market was modelled. The models ostensibly represented the view of the Refining Strategy staff but consultation which other individuals allowed the views of the local Trading department to be represented too. The tools of system dynamics were used to articulate assumptions and to support a 'dialogue' in which disagreements regarding macro-behaviour were transformed into debates over specifics relationships. The repeated re-crafting of a STELLA model led to alterations in the interaction. In consequence, the participants aligned behind a single view of the market's behaviour, as well as admitting to increased respect for the expertise of the other group.
Building Cognitive Feedback into a
Microworld Learning Environment: Results from a Pilot Experiment
Paul A. Langley
Abstract: This experimental study examines how performance and learning in a system dynamics microworld environment may be improved through the provision of online cognitive feedback. Subjects are postgraduate management students at the University of Westminster, London. They participate in the experiment over a two week period, as part of graded assignment. Subjects have to complete a set of six tasks in an Oil Producers microworld, playing the Independents Producers, with a clearly defined performance objective to maximise cumulative net income over a 25 year period. The experimental design includes three different cognitive feedback treatment groups, in addition to a control group which receives no cognitive feedback at all. All groups receive outcome feedback. Treatment groups only have access to the cognitive feedback during the first three trails out of six. Mean subject performance is significantly greater for the treatment groups during the first three trials, but declines to a level comparable with the control group by trial six. Sustainable mean performance improvements are not achieved, but productivity (performance/time taken) does improve significantly by the end of experiment.
System Dynamics and The Internet
Nan Lux
Eric Choi
Abstract: As the 21st century approaches, the Internet will be an important resource for system dynamists. This paper will describe the new computer server where a suite of Internet tools are used and maintained at MIT by the System Dynamics in Education Project under the supervision of Professor Jay Forrester. These tools will be available to anyone with an interest in system thinking and system dynamics. This introduction to the field of electronic networking will mention the various methods of connecting to the Internet and touch upon some of the most popular uses of the Internet. We will expand this discussion into how the Internet can be used for the rapid exchange of information. One of the most intriguing capabilities of the server will be the sharing of computer models. These computer simulations can be downloaded, evaluated, modified, and sent back or on to other people. The use of technology will facilitate discussion, debate, and the exchange of ideas. The MIT system dynamics server can be reached through the World Wide Web, FTP, Gopher, and e-mail. Specific detail will be given about how to access the server, and how to use each of its components. Since technology is changing rapidly, future plans for the expansion of the server will be discussed as well. A summary of what papers, models, announcements, and resources are presently available on this system dynamics server will be present. In addition, we will discuss other system dynamics resources available on the Internet, such as servers maintained by the System Dynamics Society and other institutions around the world. The technology transfer that the Internet allows can benefit all those who are interested in the field of system dynamics including model building and sharing of experiences. The Internet is an efficient, often inexpensive means of communication, which can important for the growth of system dynamics in the future.
Frank H. Maier
Abstract: Industrial companies can be characterized as complex and dynamic systems that are only parts of more complex systems. Therefore the purpose of education of business administration student can only be to teach the principles of different functional areas. Management education also has to enhance the understanding of how the different organizational parts of a company interact, how the dynamic consequences of decisions are and how decisions in one functional areas of a company influences other parts. Here the traditional way of teaching in management education fails. Tools are needed that allow (1) to teach the structural fundamentals of companies and (2) to part of the education of students in business administration at the Industrieseminar of the Mannheim Univeristy. The paper discusses a comprehensive model of a company and its interactions to the suppliers, the markets, the competitors and its use in management education. This management simulator is partly based on the model developed and published by Lyneis. Some of the sectors of the original Lyneis model were improved and completed by others that map market dynamics, research and development, and a more detailed representation of competitive structures. Opposed to the Lyneis model which was developed in DYNAMO the management simulator is implemented in VENSIM. Students use this model in t