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- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The paper describes eight problems within the Cable Division of Standard Telefon og Kablefabrik A/S which are currently being analyzed using system dynamics. Problem 7, concerned with information system projects, is described in detail.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- A generic model of adaptive systems behaviour is developed in causal loop form. Examples from many different living systems are given. Living systems do adapt: plants turn towards the light; birds fly south in the winter; people acquire a taste for champagne; revolutionaries become government bureaucrats; and cultures have dealt with horseless carriages and jet travel. Living systems also collapse: lakes get polluted and die; dinosaurs are no more; people commit suicide; there is no more Federalist party; and the Indian Nations of North America have all disappeared. As a system dynamist I am interested in the attribute or, more exactly, the minimal set of attributes of all these systems that can explain the capability to adapt and also the obvious limits to that same capability.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The acronym “MDS” refers to the methodology and a series of computing techniques which are suitable for the simulation of corporate processes. These “Dynamic Models for Corporate Strategies” allow the description of such processes as structures of a unified nature, into which one may insert all the necessary data (real or hypothetical) deriving from the initial and boundary conditions, to clearly define the possible future developments being studied. With respect to other, currently available, decisional aids, MDS differs both by its purely simulative approach and by its use of the basic descriptive structure capable of completely representing the dynamism of corporate phenomena. Compared to a “company microcosm” description using the now classical methods of Industrial Dynamics, MDS offers open and interactive systems also introducing several “corporate variants”. (These correspond both to certain types of sub-division of the complete system into given sub-system, and to relationships which may also be described in the same terms, such as the ‘accounts plan’, for example). The main aim of this paper is to analyse the effects of promotional activity- recently developed in Italy amongst medium and large companies- whose main objective is the introduction of MDS as an imprtant instrument in the practice of corporate planning.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The System Dynamics National Model represents a typical, modern, industrial economy. Although parameters have been chosen for the United States, the behavior modes exhibited by the model are those being experienced in most economies in Western developed countries. The National Model incorporates a wide range of dynamic structures that allow its behavior to span from the short-term business cycle of 3-to-7 year periodicity to the much longer-term behaviors represented by growth and by major depressions that recur at intervals of some fifty years. The System Dynamics National Model has been under development for about twelve years. An evolutionary process has been followed during which we have extended the scope of the model, added sectors, identified and corrected misbehavior, and simplified unnecessarily complex structures. There have been more than a thousand modifications and extensions of the Model. The National Model is now close to meeting our primary objectives, and we have started writing four books describing the Model and its implications for economic behavior.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The interaction between the speaker and his audience is a subject of universal interest, especially to professionals. It is a subject, moreover, requiring a dynamic method of analysis. This paper presents a conceptual model of public speaking. The purpose of this preliminary study is to identify the essential factors needed for (1) the effective delivery of a prepared speech in a conversational manner and (2) the growth of the speaker's abilities over time. As a result of my preliminary analysis of the feedback loops operating during a technical presentation, my approach to teaching novice speakers has changed. One benefit of my new approach is that it accelerates the process by which novices develop the competencies they need to give successful informative speeches. Further study of the interaction between speaker and audience using System Dynamics will contribute significantly to our understanding of human communication.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The purpose of this model is to gain insight into the relationship between poverty and AFDC assistance, to diagnose and explain causes and- on the basis of these findings- to test policy alternatives to alleviate poverty.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- Practitioners of system dynamics working in the government sector will often operate in environments filled with administrative complexities and bureaucratic inconsistencies. Some examples of less than ideal conditions encountered in a fairly large policy planning effort are here offered for the student of system dynamics.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- The Algarve province in southern Portugal has been undergoing a rapid growth due to a large increase in tourist demand. The mismanagement of the region’s water resources is leading those growth trends to halt. This paper introduces a model developed to provide a needed rational framework for Algarve water resources management, interfacing a system dynamics model with multiobjective programming formulations. The definition of water supply and demand sectors, on a spatially disaggregated basis, is an essential component of the model, with attempts to provide a tool to evaluate the effects of different strategies controlling water supply and demand upon a set of impact variables. To select an optimal strategy one has to solve a multiobjective programming problem, where the components of the objective function are the impact variables referred above. Solution methods include the analytic hierarchy process and the value display approach. The model written in Z-BASIC was run using a simulation period of 10 years.
-
- Type:
- Document
- Fecha de Creacion:
- 1984
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- dcf80aca09fd0af264c0472357441115, 23d738ba88f8333bc39725f9cb5bd0b8, and 6e5cbea1fd05527880f389afd8fb85d1
- Descripción:
- Case studies of regulatory and social programs suggest that policy systems are dynamic. In the systems described, outcomes depend on how variables interact over time, and feedback among variables--“simultaneous” causation over multiple time periods--is more a rule than an exception. However, the most influential evaluations of public programs are studies using multiple regression. A recognized limitation of multiple regression is its relative insensitivity to multiperiod strategies, feedback among variables, and other dynamics. Accordingly, we maintain, the findings of regression-based and case studies commonly conflict. Simulation modeling can serve as a methodological bridge between case studies and regression-based studies of policy systems, improving theoretical models of the system and providing a way to evaluate the robustness of alternative regression models. The results of some early experiments along these lines are presented.
-
- Type:
- Document
- Fecha de Creacion:
- 1983
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, cf82ceba47eedd73f41b00918de16477, and b0aa2a699b54f0d19f6a9d93bdbcfa18
- Descripción:
- System Dynamics as a methodology has traditionally been concerned with the study of processes that can be described by continuous variables. Discrete or integer events, such as the number of sales made in a day or the number of factory closings in a year have either been approximated as continuous variables or else not dealt with. This paper examines another way of dealing with discrete events through the realization that any discrete event has a certain probability of occurance. These probabilities are continuous and conserved quantities and can be modeled as system dynamic levels. Treating probabilities as levels in dynamic simulations is a standard technique in stochastic modeling, markov models being one example. System dynamics' advantage over these other methods is that it can represent the impact of the results of the probabilistic study of the social feedback systems. This paper focuses on examples demonstrating the use of system dynamics to model uncertain events. These examples deal with the simple case of a Poisson process with a time varying event arrival rate. Extensions incorporating conditional and independent probabilities are also considered.