Abstract sobre la tematica dinamica de sistemas

Introduction to the system dynamics

The system dynamics is a methodology and a technology of simulation for computer to fit, to understand and to discuss situations and complex problems. Originally developed in 1950, to help the corporate administrators to improve his understanding of the industrial processes, the system dynamics is used nowadays in the sector public and deprived for the analysis and design of policies.
The system dynamics like method to understand the dynamic behavior of complex systems is an aspect of the TGS. The base for the method is the recognition of which the structure of any system is often so important to determine his behavior as the individual components. Some examples are the theory of the chaos and the social dynamics. Also it is said often, that since there are properties completely that they cannot be found between the properties of the elements at the time the behavior completely it cannot be explained in terms of the behavior of his parts.
For a better comprehension of the system dynamics it is necessary bear the following concepts in mind:

Theory of the chaos

Theory of the chaos is the popular name of the branch of the matemática, the physics and other sciences that it treats certain types of dynamic systems very sensitive to the variations in the initial conditions. Small variations in the above mentioned initial conditions, can involve big differences in the future behavior; complicating the long-term prediction. This happens though these systems are deterministic, that is to say; his behavior is completely determined by his initial conditions.

Social dynamics

The sociology allows us to understand the structure and dynamics of the Company Humanizes, in his diverse manifestations, of the social conduct of individuals belonging to groups determined to that of institutions and organizations with different forms and degrees of entail with national communities national supra (corporations - agreements) or intranacionales (regions).
 It examines the expressions of the social structure, classes, sex, age, race, occupation, etc;. As well as the forms of institutionalization that they acquire across the government, other ways of being able, the politics, economy, religion, culture. It examines also how individuals and collectivities, construct, they support and alter the social organization;.The sociologist wonders brings over of the origins and consequences of the social change, how there are achieved the social agreements, the consensus or the domination and his duration or permanency.
 In the examination of the social dynamics there are included the elements belonging to other disciplines that study elements of the same social field; as the population (Demography), the rationality (Economy) and the context (bought) in the production of his goods and services, the values and customs acquired (Anthropology), the individual conduct (Psychology), his language and (Linguistic) literature and his remote or recent past (Tells the history), For the sociologist these disciplines provide the exogenous variables when they try to explain the key components of the socialization to him, the power, control, cooperation,Social violence, order and change. With the aim to contribute to the exposition of alternatives to the management, planning and / or transformation of the institutions.






System dynamics


The system dynamics combines the theory, the methods and the philosophy to analyze the behavior of the systems (according to Jay Forrester).
 The system dynamics arose from the search of a better comprehension of the administration but nowadays his application to extended now at the rate of the environmental way, the engineering, the medicine, the economic and social conduct and mas recently to the politics.
 The system dynamics shows since the things are changing to travez the time. A project of system dynamics begins with a problem that it is necessary to resolve in an undesirable behavior that it is necessary to correct and to avoid.


Another concept of system dynamics




 It is a methodology for the model construction of simulation for complex systems, the system dynamics applies methods of hard and soft systems


 Methodology of soft systems


 The Methodology of soft systems (SSM for his initials in English) of Peter Checkland is a qualitative technology that can be in use for applying the systems structured to the situations to him asistémicas. It is a way of dealing with situational problems in which there is an activity with a high social, political and human component. This distinguishes the MSB of other methodologies that deal with the HARD problems that are more orientated often to the technology. The MSB applies the systems structured to the current world of the human organizations. But crucially assuming that the topic of the investigation is in yes same is a simple system. The SM therefore is a useful way of approaching complex situations and the untid corresponding questions.


This one uses methods of quantification and validation:




 Quantification: It is begun for identifying the variables of interest and the relations that stop between if these variables.
 Validation: Once constituted the model it is necessary to ask if if it reflects reasonably the reality.


Dynamical Systems in System Dynamics simulation allows for paths to the variables included in any model by applying numerical integration techniques. However, these paths are never interpreted as predictions, but as projections or trends. The purpose of the System Dynamics models is, as in all soft systems methodologies, to understand how the structure of the system is responsible for his behavior. This understanding should normally produce a favorable environment to determine actions that can improve system performance or solve the identified problems. The advantage of system dynamics is that these actions can be simulated at low cost, making it possible to assess their performance without putting them into practice on the real system.

Dynamical Systems

In System Dynamics simulation allows for paths to the variables included in any model by applying numerical integration techniques. However, these paths are never interpreted as predictions, but as projections or trends. The purpose of the System Dynamics models is, as in all soft systems methodologies, to understand how the structure of the system is responsible for his behavior. This understanding should normally produce a favorable environment to determine actions that can improve system performance or solve the identified problems. The advantage of system dynamics is that these actions can be simulated at low cost, making it possible to assess their performance without putting them into practice on the real system.

In System dynamics the simulation allows to obtain paths for the variables included in any model by means of the application of technologies of numerical integration. Nevertheless, these paths are never interpreted as predictions, but as projections or trends. The object of the models of System dynamics is, since it happens in all the methodologies of soft systems, to manage to understand how the structure of the system is responsible for his behavior. This comprehension normally must generate a favorable frame for the determination of the actions that could improve the functioning of the system or solve the observed problems.

The advantage of the System dynamics consists in that these actions can be simulated to low cost, with what it is possible to value his results without need to put them into practice on the royal system.

A dynamic system is a complex system, which presents a change or evolution of his condition in a time, the behavior in the above mentioned condition can be characterized determining the limits of the system, the elements and his relations; of this form it is possible to elaborate models who seek to represent the structure of the same system.

On having defined the limits of the system there is done, first, a selection of those components that help to generate the manners of behavior, and then the space decides where the study will be carried out, omitting all kinds of irrelevant aspects.
 As for the production of the models, the elements and his relations, it is necessary to to bear in mind:

A system is formed by a set of elements in interaction.
 The behavior of the system can appear across causal graphs.
 There are several types of variables: exogenous variables (they are those that concern the system without this one provokes them) and the endogenous variables (they concern the system but this one yes it provokes

An example of a dynamic system can be seen in a species of fish that is reproduced in such a way that this year the quantity of fish is Xk, next year will be Xk + 1. Hereby we can put names to the quantities of fish that will exist every year, this way: initial year X0, the first year X1........... ......, year k Xk.

 Since it is possible to observe:, it is fulfilled for any year k; which means that the quantity of fish can decide if there is known the quantity of the previous year. Consequently this equation represents a dynamic system.