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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- This paper explores the use of geneticalgorithms (GAs) for optimizing system dynamics models. System dynamics offersa unique and powerful approach to identifying the most successful policies formanaging complex problems. Unfortunately, policy makers too often avoid the useof models because of high level of experience required to operate the modelsand the time and expense which results from trail and error testing of amultitude of policy options in order to discover the best policies. The role ofsystem dynamics models as decision-makers tools would be greatly strengthenedif model users could simply identify the goals for the system being modeled andhave the system dynamics model identify the best management actions. Current analysisand optimization techniques used with system dynamics models are not capable ofautomatically determining which policies most nearly produce the desired systembehavior. One emerging optimization technique, (GAs), offers great promise inautomating the identification of the best policies for selected system goals.
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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- We have done research fore these 20 years on the model for dental diseases in Japan. We started from 2 sector of demography and dental caries, then added pyorrhea, baby teeth and technology sectors.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- Top management, through strategic plan, designs the guide of actions that are necessary to achieve company goals. Methodologies and tools are essential for comparing the results reached through operative actions with those programmed; so that the management can analyze the differences and decide operations to better manage the future. In this area the principle aim is to support, who has the decision, with instruments that increase management knowledge. As a whole, the control system, is "simply" an overall feedback model, the results of which, if given in time to top management, allows him/her corrective actions that can be "vital" for company conduction. Above knowing how things are going compared to what has been planned, top management needs to know which are the so called "master variables" that have particularly influenced the results. What will describe in this paper will be the following: how, through System Dynamics approach, a simple "feedback control" management model can be integrated with a "feed-forward System" so to support top management in the process of budget planning and management control. Two problems will be particularly discuss that could be of interest. - An application of dynamic problem definition as a prerequisite to a good System Dynamics modeling. This theoretical approach will be integrated also with an approach that imposes to define an aggregate model which contains, particularly, "master variables". - The model will be discussed and developed together with an academic expert in Italian public accounting and this will be a way to spread out the knowledge in System Dynamics approach in Italian university environment. The result model will support public managers in the process of budget plan and the management control.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- With the advent of concepts such as punctuated equilibrium, chaos, and systems thinking from the hard sciences, and their respective implications for the social science, we must consider change to be more performance; it requires us to examine both the organization's ability to perform and their collective ability to learn. This perspective necessitates the use of a sociological paradigm which allows for a better understanding of the dynamic and complex nature of organizational learning. The organizational systems model discussed in this essay contains four subsystems each responsive for carrying out vital functions for the organizational learning system to adapt to its environment. Relationships among the subsystems is established through the use of input/output variables labeled as interchange media: new information, goal referenced knowledge, structuring, and sense making. These interchange media are products of the functional subsystems of the organizational learning system and are manifested and measurable dynamics variables. Qualitative data is used to provide illustrative case examples. The paper concludes with implications for the system modeling of organizational change as a function of both performance and learning.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- The lack of commonly held rules or standards for system dynamics, the eclecticism of its application, and the wide variety of modeling and non-modeling methodologies developed over the past thirty years present formidable challenges for establishing an effectively functioning system dynamics community. It is reasonable to suggest that the current structure of the community may hold back the growth of the field more than obvious obstacles such as the inherent difficulty of developing insightful moods or the counterintuitive nature of nonlinear feedback lessons. In this light, the structure of the community deserves closer scrutiny. Benchmarking the System Dynamics Community, a survey sent by the author to System Dynamics Society members in February of 1993, is the first survey of the system dynamics community and a first step towards developing a more comprehensive understanding of the structure of the field. The survey instrument consisted of five sections: background, Practice, Software, and Hardware, Model Building, and History Development, and Community. The survey was designed to isolate where system dynamics is practiced, by whom and for what; understand how the methodology is applied and identify lines of communication across the field. This paper presents the results of survey response, structured parallel to the five sections of the survey instrument. It concludes with a series of questions for further investigations.
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- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- System dynamics has strong didactic potential of physics education. The use of modeling systems like Stella in the physics classroom creates new opportunities to - accentuate the basic structure of physical theories, - investigate more complex and realistic phenomena, - improve the possibilities for students to bring in their own ideas. Conventional physics instruction is often dominated by a bulk of special equations (gimmicks) for special cases, like s=v.t for linear motions on an air track. System dynamics models help students to realize that the core of physics can be expressed by a limited number of power tools like Newton's laws _p=F._t, which are applicable to a wide range of topics, including process and the graphical modeling language, they can use system dynamics as a tool to solve problems from nearly all domains of physics, starting from the motion of bodies to the decay nuclei. Empirical research carried out by the University of Bremen has documented case studies about the use of STELLA over three years of high school physics courses. A comprehensive selection of modeling examples ranges from the motion of meters over electromagnetic vibrations to Rutherford scattering. Our empirical finding shows a) that using systems dynamics methods is feasible in normal physics classes, and b) that content, methods and results of physics teaching are improved. The paper presents the didactic rationale and selected examples.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- A system Dynamics model of a dual economic system incorporating also the behavioral responses to competition and the ability to innovate on the part of the formal and self-employed sectors is developed and used as an experimental apparatus to search for technology-related entry points for achieving economic growth and changing income distribution. Policies to promote competition among the monopolistic formal fi9rms while simultaneously providing positive assistance to the competitive informal firms appear to offer promising alternatives to the traditional fiscal policy levers mainly affecting prices and factor costs.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- A desirable movement towards a high skill and high wages economy may imply a broader employee participation in shaping investment/innovation strategies. This could extend collective bargaining over automating, timing of innovations in addition to issues involving employment, wages and other working conditions. This paper makes us of nonlinear differential equations and of a qualitative state space analysis to describe dynamic feedback system, based upon a Goodwin-like model of economic cyclical growth and income distribution. The patterns of behavior are traced to the system's feedback structure (in particular, to delays and polarity of it's feedback link and loops). It is shown that typically growth of labor productivity promotes a steady state labor bill share and employment ratio, although irrationality or myopic rationality in bargaining, disregarding regularities of the whole system, may be detrimental.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- This paper reflects on a successful problem solving exercise that was carried out in a textile factory using a systems approach together with a Japanese management technique. The systems approach used was System Dynamics modeling and the Japanese management technique was CEDA (see appendix). The paper concludes that successful problem solving can be viewed as a group of learning process and that this approach offers a useful framework for initiating and managing performance improvement. The degree of success is largely determined by the degree of learning that takes place.
-
- Type:
- Document
- Date Created:
- 1994
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, c060552994c1527f70693734935660f1, and fe35db792b573af835d96e6eba4759cd
- Description:
- In the study presented here we have modeled a firm with various production sections managed along traditional lines. We also include in the model the structural changes necessary for the company to be managed according to OPT. It is possible to work with the two philosophies alternately. We have thus created a tool which allows us to check the validity of the various basic rules from which professor Goldratt works in developing his theory, and also to establish its strengths and/or possible weaknesses for different business situations.